Evolutionary explanations of food preferences | AQA A-Level Psychology Revision

For 7182 specification, first teach in September 2025

AQA A-Level Psychology | Free Revision Notes

Estimated study time: 60 minutes

Evolutionary explanations propose that human food preferences developed because they helped our ancestors survive and reproduce. These Evolutionary explanations of food preferences A-Level Psychology revision notes examine why people may be predisposed to prefer energy-rich foods while avoiding unfamiliar or potentially poisonous substances. You will explore preferences for sweetness, fat and salt, together with neophobia and taste aversion. The current AQA specification requires the evolutionary explanation of food preferences, including explicit reference to neophobia and taste aversion.

Learning Objectives 🎯

By the end of this revision page, you should be able to:

• Explain how natural selection may have shaped food preferences.

• Explain the adaptive value of preferences for sweet, fatty and salty foods.

• Define and explain food neophobia.

• Define and explain taste aversion.

• Distinguish clearly between neophobia and taste aversion.

• Apply evolutionary explanations to unfamiliar examples of food choice and avoidance.

• Evaluate evolutionary explanations using psychological research and alternative influences.

Revision Notes 📚

Evolutionary explanations of food preferences overview

A food preference is a tendency to select, enjoy or avoid particular foods or flavours.

Evolutionary explanations propose that some preferences and avoidances are at least partly innate because they increased the chances that our ancestors would:

• Obtain enough energy.

• Consume necessary nutrients.

• Avoid poisonous substances.

• Survive illness and environmental hardship.

• Reach reproductive age.

• Raise offspring successfully.

The basic evolutionary pathway is:

variation in food-related behaviour → some preferences improve survival → individuals with those tendencies reproduce → associated characteristics become more common

AQA mark schemes describe the evolutionary explanation as the idea that preferences and avoidances which aided survival became increasingly prevalent within the population. They also recognise specialised taste receptors and preferences for sweetness, salt and fat as relevant examples.

Natural selection

What is natural selection?

Natural selection is the process through which inherited characteristics that improve survival and reproduction become more common over generations.

Within a population, individuals vary.

Some ancestral humans may have been more likely to:

• Seek sweet foods.

• Prefer calorie-dense foods.

• Detect bitterness.

• Avoid unfamiliar plants.

• Form rapid aversions following illness.

Where these tendencies helped individuals survive, those individuals were more likely to:

• Reach reproductive age.

• Produce offspring.

• Pass on the relevant biological predispositions.

Over many generations, adaptive preferences could become widespread.

Survival and reproductive success

Evolution does not select characteristics because they are healthy in every possible environment.

A characteristic is favoured when it improves reproductive success, meaning the likelihood that genes are passed to future generations.

For example:

A preference for energy-rich food may have helped an ancestral person survive a period of food scarcity.

That preference could be adaptive even if eating too much energy-rich food creates health risks in a modern environment where such foods are continuously available.

Adaptation

An adaptation is a characteristic shaped by natural selection because it solved a recurring survival or reproductive problem.

Food-related adaptations may include:

• Attraction to tastes associated with useful nutrients.

• Rejection of tastes associated with toxicity.

• Caution towards unfamiliar foods.

• Rapid learning after food-related illness.

Proximate and ultimate explanations

Proximate explanation

A proximate explanation concerns the immediate mechanism producing behaviour.

For example:

A person selects a biscuit because its sweet taste activates sensory and reward processes.

Ultimate explanation

An ultimate explanation concerns why the tendency may have evolved.

For example:

Sweetness was historically associated with energy-rich foods, so attraction to sweetness increased survival.

Evolutionary explanations are mainly ultimate explanations.

They attempt to explain why a preference exists across the human population, rather than only why one person chose one food during one meal.

Ancestral and modern environments

Evolutionary explanations refer mainly to the environments in which human food preferences developed.

In ancestral environments:

• Food supply was less predictable.

• Starvation could present a serious risk.

• Energy-rich food could be difficult to obtain.

• There were no modern food labels.

• Eating an unfamiliar plant could be dangerous.

• Rapid detection of possible toxins was valuable.

Preferences that were adaptive under those conditions may still influence food behaviour today.

Evolutionary mismatch

An evolutionary mismatch occurs when a characteristic adapted to an earlier environment becomes less useful, or potentially harmful, under modern conditions.

For example:

A strong preference for high-calorie food was useful when food was scarce, but may encourage overconsumption where inexpensive energy-dense food is continually available.

This does not mean that the original evolutionary explanation is incorrect.

It means that:

• The environment changed faster than inherited predispositions.

• A formerly adaptive preference may have different consequences today.

This connects with later explanations of genetic and neural influences on weight gain [Biological explanations of obesity] and restraint and disinhibited eating [Psychological explanations of obesity].

Preference for sweet foods

Why sweetness may be adaptive

Sweetness is commonly associated with carbohydrates and readily available energy.

Energy is required for:

• Movement.

• Maintaining body temperature.

• Brain functioning.

• Growth.

• Reproduction.

• Caring for offspring.

An ancestral preference for sweetness could therefore have encouraged people to consume foods likely to provide usable energy.

The 2021 AQA mark scheme applied this reasoning directly to a child preferring peas and biscuits, noting that sugar provides fast-acting energy with potential survival value.

Sweetness and safe energy

Sweet plant foods may also have been less likely to contain dangerous toxins than intensely bitter substances.

A preference for sweetness could therefore signal:

• Energy.

• Ripeness.

• Relative safety.

The relationship is not perfect because:

• Not every sweet food is nutritious.

• Not every non-sweet food is unsafe.

• Modern manufactured foods can contain very high concentrations of sugar.

Evolutionary preferences guide probability rather than providing an infallible safety system.

Taste receptors

AQA’s 2021 mark scheme accepts the idea that specific genes contribute to specialised taste receptors, including genes associated with detecting sweetness.

The important exam point is:

Humans possess biologically based systems capable of detecting tastes that had survival significance.

Students do not need a lengthy molecular account to explain the evolutionary theory effectively.

Preference for fatty foods

Why fat may be adaptive

Fat contains a high amount of energy.

In an environment where meals were uncertain, fatty food could provide:

• Concentrated calories.

• Stored energy.

• Support during future food scarcity.

• Energy for physically demanding activity.

• Energy needed during pregnancy and childcare.

Individuals attracted to fatty foods may therefore have been better able to survive periods when food was unavailable.

Application to food choice

A child strongly prefers a fatty roast dinner to a low-calorie unfamiliar meal.

An evolutionary explanation might suggest that:

• Fat is calorie dense.

• A preference for high-energy foods offered survival value in ancestral environments.

• The child may possess an inherited predisposition towards such tastes.

The 2021 mark scheme accepted the high calorie content of roast dinners as an evolutionary application.

Modern consequences

In modern environments:

• Fatty food can be easily available.

• Little physical effort may be needed to obtain it.

• Food scarcity may be uncommon for many individuals.

• Portion sizes can be large.

The evolved preference may therefore contribute to consuming more energy than is required.

This is an example of evolutionary mismatch rather than proof that all high-fat food preferences are entirely innate.

Preference for salty foods

Why salt may be adaptive

Salt is necessary for normal bodily functioning.

A preference for some salt may have encouraged ancestral humans to obtain an important but potentially limited nutrient.

The evolutionary account predicts attraction to suitable quantities rather than an unlimited preference for salt.

Moderation matters

A preference can be adaptive within one range but harmful when the substance is available in excessive quantities.

The evolutionary explanation does not claim:

• More salt is always better.

• Every individual likes equally salty food.

• Culture has no influence on salt intake.

Instead, it proposes an underlying predisposition that can be modified by experience.

Avoidance of bitter tastes

Bitterness as a danger signal

Many naturally poisonous substances have a bitter taste.

Sensitivity to bitterness could therefore help ancestral humans avoid:

• Toxic plants.

• Spoiled substances.

• Chemically dangerous food.

• Foods likely to produce illness.

The possible evolutionary pathway is:

bitter taste → possible toxicity → avoidance → reduced poisoning risk

AQA mark schemes accept avoidance of bitter foods as an example of taste aversion and note that humans may require particularly fine discrimination between different bitter tastes because bitterness can signal danger.

Bitterness is an imperfect signal

Not every bitter substance is poisonous.

Some safe or nutritious foods taste bitter.

Therefore:

• Avoiding all bitterness would restrict the diet.

• Experience may teach people that particular bitter foods are safe.

• Cultural practices can increase acceptance of initially disliked tastes.

Evolution provides a cautious starting point, while learning modifies the final preference.

Selection pressures in food choice

A selection pressure is an environmental challenge affecting survival and reproduction.

Important food-related selection pressures may have included:

• Food shortage.

• Nutritional deficiency.

• Poisonous plants.

• Spoiled food.

• Illness after ingestion.

• The difficulty of distinguishing safe from unsafe foods.

Different tendencies may have evolved in response to different pressures.

Selection pressure	Possible adaptive response
Unpredictable food supply	Preference for energy-rich food
Need for rapid energy	Preference for sweetness
Need for concentrated calories	Preference for fat
Need for essential minerals	Preference for salt
Risk from poisonous plants	Avoidance of bitterness
Risk from unfamiliar substances	Neophobia
Illness after eating	Taste aversion

Food approach and food avoidance

Evolutionary explanations account for both:

Approach preferences

The person is attracted towards foods likely to offer benefits.

Examples include:

• Sweet food.

• Fatty food.

• Salty food.

Avoidance preferences

The person avoids foods carrying possible danger.

Examples include:

• Unfamiliar food.

• Bitter substances.

• A flavour previously associated with illness.

Both systems could improve survival.

An organism that approached every available substance would risk poisoning.

An organism that avoided every available substance would risk starvation.

Adaptive eating requires a balance between:

obtaining nutrients and avoiding danger

Neophobia

What is neophobia?

Neophobia is an innate fear, dislike or avoidance of new and unfamiliar foods.

The term can be divided into:

• neo, meaning new

• phobia, meaning fear or avoidance

AQA’s 2023 question described neophobia as an innate fear of unfamiliar foods.

Core features of neophobia

Neophobia involves:

• A food the person has not previously encountered.

• Reluctance or refusal before the food has been safely experienced.

• Caution based on unfamiliarity itself.

• A tendency often observed in younger children.

The food does not need to:

• Be poisonous.

• Taste bitter.

• Have caused illness previously.

• Be disliked permanently.

The central feature is newness.

Valid example

A young child refuses to taste an unfamiliar vegetable that has just been placed on their plate.

This is neophobia because:

• The vegetable is unfamiliar.

• The child avoids it before learning whether it is safe or enjoyable.

AQA’s 2024 mark scheme gives babies avoiding new vegetables as a valid example.

Invalid example

A child refuses broccoli because they ate it previously and disliked its bitterness.

This is not a clear example of neophobia because the food is not new.

It may instead involve:

• Taste aversion.

• A learned dislike.

• Sensitivity to bitterness.

Why neophobia may have evolved

Protection from poisoning

Young children become increasingly mobile and able to select objects and foods independently.

Caution towards unfamiliar substances may reduce the likelihood of eating:

• Poisonous berries.

• Toxic plants.

• Spoiled food.

• Harmful objects.

The adaptive sequence is:

unfamiliar substance → cautious avoidance → reduced exposure to poison → increased survival

Survival value

A child who immediately ate every unfamiliar object or plant might face greater poisoning risk than one who approached unfamiliar substances cautiously.

Individuals with a tendency towards neophobia may therefore have been more likely to survive.

The tendency could then become widespread through natural selection.

Neophobia does not need to be permanent

The most adaptive system would not require lifelong refusal of every new food.

Instead:

• Initial caution protects against immediate danger.

• Observation and safe exposure provide information.

• Repeated safe experiences can increase acceptance.

Learning can therefore modify an evolutionary predisposition.

This interaction is developed in social, cultural and associative influences on preference [Learning and food preferences].

Neophobia and age

Neophobia is especially relevant to children because childhood involves:

• Increasing independent movement.

• Encountering unfamiliar substances.

• Limited knowledge of toxicity.

• Dependence on adults for information about safety.

AQA’s 2024 mark scheme notes that neophobia usually occurs in young children, although unfamiliar-food avoidance can occur more broadly.

Why children may reject vegetables

Vegetables may be:

• Unfamiliar.

• Bitter.

• Different in texture.

• Less energy dense than sweet foods.

A refusal may therefore reflect more than one influence:

• Neophobia towards newness.

• Taste aversion towards bitterness.

• Preference for sweetness.

• Limited exposure.

• Modelling by adults.

A strong psychological explanation should identify the precise clue in the scenario.

Neophobia and repeated exposure

Neophobia concerns the initial avoidance of unfamiliar food.

When a food is encountered repeatedly without harmful consequences:

• It becomes familiar.

• The danger signal may weaken.

• Acceptance may increase.

This does not disprove the evolutionary explanation.

An adaptive system could involve:

1. Initial caution.

2. Gathering information.

3. Gradual acceptance when safety is established.

The detailed role of exposure belongs to learning and cultural influences on food preferences [Learning and food preferences].

Applying neophobia

Scenario 1

Ravi eats carrots regularly but refuses a purple vegetable he has never seen before.

This is consistent with neophobia because:

• The purple vegetable is unfamiliar.

• Ravi avoids it before tasting it.

• The newness of the food appears to produce the avoidance.

Scenario 2

Ava ate mushrooms last week, became ill and now refuses them.

This is not neophobia because:

• Mushrooms are no longer unfamiliar.

• The avoidance developed after illness.

This is taste aversion.

Scenario 3

Noah refuses every vegetable, including vegetables he has eaten safely for several years.

This cannot be explained fully through neophobia because the foods are familiar.

Other explanations may include:

• Taste aversion.

• Learning.

• Family influence.

• Cultural preference.

• Sensory sensitivity.

Evaluating neophobia

Adaptive value

Neophobia has clear potential survival value.

Avoiding unfamiliar foods could reduce the risk of poisoning before the person has learned which foods are safe.

This is particularly useful for young children exploring their environment.

Possible modern disadvantage

Strong neophobia may restrict dietary variety.

A person may avoid unfamiliar but nutritious foods, including:

• New vegetables.

• Fruit.

• Foods from other cultures.

A once-adaptive caution can therefore become inconvenient where food safety is already controlled.

Learning can override neophobia

Children may become willing to eat unfamiliar foods after:

• Seeing trusted adults eat them.

• Repeated safe exposure.

• Positive social experiences.

• Cultural familiarisation.

This suggests that neophobia is not a fixed determinant of preference.

It provides an initial bias that can be modified by experience.

Taste aversion

What is taste aversion?

Taste aversion is a tendency to dislike or avoid a particular flavour or food associated with danger, toxicity, bitterness or illness.

A taste aversion may be:

• Innate, such as caution towards bitterness.

• Learned after a food is followed by sickness or nausea.

AQA’s 2024 mark scheme distinguishes taste aversion from neophobia by explaining that taste aversion is based on danger, toxicity or bitterness and can be innate or learned.

Core features of taste aversion

Taste aversion involves:

• A specific food or flavour.

• Avoidance because it signals possible harm.

• Previous illness or toxic association in many cases.

• Possible occurrence at any age.

The food does not have to be unfamiliar.

Indeed, a familiar and previously enjoyed food can become strongly disliked after illness.

Valid examples

AQA has accepted examples including:

• Avoiding a bitter food such as broccoli or sprouts.

• Rats avoiding poison-laced bait.

• Rats avoiding sweet liquid after it was paired with lithium chloride.

• Avoiding ice cream following nausea-inducing chemotherapy.

Evolutionary value of taste aversion

Preventing repeated poisoning

Suppose an organism eats a particular food and later becomes ill.

Avoiding the same flavour in future could prevent:

• Repeated poisoning.

• Further illness.

• Death.

Individuals able to connect taste with illness may have been more likely to survive.

The adaptive pathway is:

flavour consumed → illness follows → flavour avoided later → reduced chance of repeated poisoning

Biological preparedness

Biological preparedness is an inherited readiness to form particular associations more easily than others.

Humans and other animals may be especially prepared to associate:

• Taste with nausea.

• Food with digestive illness.

• Bitterness with toxicity.

This makes evolutionary sense because those associations address recurring survival threats.

AQA’s 2020 mark scheme interprets taste-aversion findings as evidence that organisms are prepared to develop aversions that keep them safe.

Innate and learned taste aversion

Innate taste aversion

An innate aversion is present without a particular personal learning episode.

For example:

A child immediately rejects a strongly bitter substance.

The bitterness may function as an inherited warning signal.

Learned taste aversion

A learned taste aversion develops after a particular food is associated with illness.

For example:

A person enjoys strawberry ice cream, becomes severely nauseous after eating it and later feels sick when they smell strawberry ice cream.

The food may not have caused the illness.

The association can still develop if it was a noticeable taste experienced before nausea.

Both forms can have evolutionary value

Innate aversion provides immediate protection.

Learned aversion allows flexible protection against dangers that cannot be predicted genetically.

An organism therefore benefits from:

• Built-in caution towards common danger signals.

• Capacity to learn from personal experience.

Conditioned taste aversion

Classical-conditioning account

Learned taste aversion can be understood through classical conditioning.

Before learning:

• The food has no aversive meaning.

• Illness naturally produces nausea.

During learning:

• The food is experienced before the illness.

After learning:

• The food alone produces avoidance or nausea.

A simplified sequence is:

food or flavour + illness → association develops → food or flavour produces aversion

The full role of classical conditioning in food choice is developed in associative learning and food preferences [Learning and food preferences].

Evolutionary interpretation

A purely general learning account might predict that many events could become associated equally easily.

Evolutionary preparedness predicts selective learning:

• Taste is particularly readily associated with nausea.

• Other events may be less easily connected with digestive illness.

This selectivity supports the view that learning mechanisms themselves have been shaped by evolution.

The Garcia effect

The Garcia effect refers to the development of a conditioned taste aversion when a particular flavour is associated with illness.

It demonstrates that:

• Food avoidance can be learned.

• Organisms are especially prepared to link taste with sickness.

• Learning is influenced by biological survival mechanisms.

AQA’s 2021 mark scheme explicitly accepts the Garcia effect as an explanation of food avoidance following a bad experience.

Garcia and Koelling’s research

Garcia and Koelling investigated learned taste aversion in rats.

Rats developed an aversion to sweet-tasting water after the flavour was paired with illness caused by poison.

The same taste aversion did not develop in the same way when the sweet water was paired with electric shock.

AQA accepts this research as evidence that taste and sickness are especially prepared to become associated.

What the research suggests

The findings suggest that learning is not completely flexible.

Rats were especially prepared to associate:

• Taste with internal illness.

They were less prepared to associate:

• Taste with an external electric shock.

This is consistent with evolutionary theory because taste is a useful predictor of poisoning, while the flavour of food is not normally the cause of an external shock.

Evaluation of the evidence

The study supports biological preparedness.

However, rats and humans differ in:

• Diet.

• Sensory systems.

• Natural environments.

• Cognitive complexity.

Findings from non-human animals should therefore be generalised cautiously.

Garcia’s work with wolves and coyotes

AQA’s 2020 mark scheme accepts research in which wolves and coyotes developed an aversion to mutton or live sheep after mutton was paired with illness induced by lithium chloride.

Findings

After becoming ill following consumption of the meat, the animals avoided:

• Mutton.

• In some cases, live sheep.

Implication

This supports the survival value of taste aversion because:

• One harmful food experience altered future behaviour.

• The animals avoided a possible source of illness.

• The learning was food-specific.

Practical implication

Conditioned aversion could potentially be used to change predatory behaviour without killing the predator.

The examination value lies primarily in showing how rapidly learned avoidance can protect an organism.

Bernstein and Webster

Bernstein and Webster investigated adults receiving chemotherapy.

Some participants developed an aversion to ice cream when it was eaten in connection with treatment that caused nausea.

AQA accepts this as human evidence of taste aversion.

What this demonstrates

The food itself did not need to be poisonous.

The aversion developed because:

• A distinctive flavour occurred before nausea.

• The person associated that food with feeling ill.

• Future avoidance protected against a food perceived as harmful.

Practical issue

Where a pleasant food is repeatedly paired with treatment-related nausea, the person may lose a previously enjoyed food preference.

This demonstrates that taste aversion can sometimes be maladaptive because the avoided food was not the real cause of illness.

Neophobia and taste aversion compared

These concepts are related but must not be treated as synonyms.

Neophobia	Taste aversion
Avoidance of new or unfamiliar food	Avoidance of a particular food or flavour associated with danger
Triggered by unfamiliarity	Triggered by toxicity, bitterness or illness association
Usually described as innate	May be innate or learned
Often associated with younger children	Can occur at any age
No previous illness is required	Often follows illness or nausea
Food may later become accepted	Aversion can continue towards a familiar food
Example: refusing a new vegetable	Example: avoiding ice cream after chemotherapy-related nausea

AQA’s 2024 mark scheme summarises the distinction as an innate dislike of newness compared with dislike based on danger, toxicity or bitterness.

The crucial difference

Ask one question:

Why is the person avoiding the food?

If the answer is:

“Because it is unfamiliar.”

the best concept is neophobia.

If the answer is:

“Because it tastes dangerous or was associated with illness.”

the best concept is taste aversion.

Worked comparison

Neophobia example

A toddler refuses an unfamiliar green vegetable without tasting it.

This is neophobia because:

• The food is new.

• No illness association is mentioned.

• The toddler’s avoidance concerns unfamiliarity.

Taste-aversion example

An adult previously enjoyed prawns but refuses them after becoming sick following a seafood meal.

This is taste aversion because:

• Prawns are familiar.

• Avoidance follows illness.

• The particular flavour has acquired an association with danger.

Why both may be adaptive

Neophobia protects the person:

before an unfamiliar food is tried

Taste aversion protects the person:

after a food has appeared to produce illness

Together, they create two lines of defence:

1. Initial caution

2. Learning from harmful experience

Neophobia and bitterness can overlap

Suppose a child rejects a new bitter vegetable.

This may involve:

• Neophobia because the food is unfamiliar.

• Innate taste aversion because it is bitter.

The concepts are distinguishable even where both influence the same behaviour.

A good exam answer should state which feature demonstrates each process.

For example:

“The child’s initial refusal before tasting the new vegetable demonstrates neophobia. If the child later rejects it because its bitter flavour signals possible toxicity, this reflects taste aversion.”

Taste aversion and learning

Taste aversion is part of the evolutionary explanation because organisms may be biologically prepared to develop it.

It is also connected with learning because a particular aversion may develop after experience.

This illustrates an interaction between:

• Innate predisposition.

• Environmental association.

The presence of learning does not remove evolutionary influence.

Evolution may have shaped what organisms are especially ready to learn.

Evolutionary explanation and the nature-nurture debate

Nature

Evolutionary explanations emphasise inherited predispositions.

Examples include:

• Attraction to sweetness.

• Avoidance of bitterness.

• Neophobia.

• Preparedness for taste aversion.

Nurture

Food preferences are also influenced by:

• Parents.

• Peers.

• Cultural norms.

• Exposure.

• Reinforcement.

• Advertising.

The most balanced conclusion is interactionist:

People may begin with evolved biases, but experience shapes the particular foods through which those biases are expressed.

For example:

• The preference for sweetness may be widespread.

• The particular sweet foods eaten depend on culture and availability.

This connects with social and cultural learning of food choices [Learning and food preferences].

Evaluating evolutionary explanations

Strength: preferences have clear survival value

The explanation provides a logical reason why people may prefer:

• Sweet foods.

• Fatty foods.

• Some salty foods.

These preferences historically helped individuals obtain:

• Energy.

• Stored calories.

• Essential nutrients.

The explanation also accounts for avoidance of:

• Bitterness.

• Unfamiliar foods.

• Foods associated with sickness.

A single survival principle therefore explains both approach and avoidance.

Strength: evidence from taste-aversion research

Garcia and Koelling found that rats developed aversion to sweet water when it was associated with poisoning but not when it was associated with electric shock.

This supports evolutionary preparedness because:

• The rats did not learn every association equally.

• Taste and internal illness formed the adaptive connection.

• The learning system appears specialised for survival-relevant relationships.

Evaluation

The controlled procedure makes the comparison between illness and shock clear.

However:

• The participants were non-human animals.

• Human food choice is strongly affected by language, culture and conscious beliefs.

• Direct generalisation should therefore be cautious.

Strength: human evidence

Bernstein and Webster’s chemotherapy research demonstrates taste aversion among humans.

This is valuable because it reduces concern that conditioned taste aversion occurs only in rats.

The research indicates that:

• A distinctive food can become disliked after nausea.

• The avoided food does not need to be the actual cause of illness.

• The association can alter later food choice.

Limitation

Chemotherapy patients experience an unusual and medically intense situation.

Their reactions may not represent ordinary food preferences in the general population.

The evidence is particularly relevant to aversion rather than every type of food preference.

Strength: infant and child behaviour

Neophobia and early rejection of bitter foods appear before extensive individual learning.

AQA accepts observations of babies rejecting bitter food as evidence relevant to naturally occurring taste aversion.

This supports an innate contribution because very young children have had limited opportunity to learn complex cultural rules.

Counterpoint

Even young children are influenced by:

• Prenatal sensory experience.

• Early feeding.

• Reactions of caregivers.

• Repeated exposure.

Early appearance does not automatically prove that a behaviour is entirely genetic.

Strength: specialised taste systems

Humans possess taste systems capable of detecting survival-relevant properties such as:

• Sweetness.

• Saltiness.

• Bitterness.

AQA’s 2021 mark scheme accepts specialised genetically influenced taste receptors as evidence within the evolutionary explanation.

The larger capacity for distinguishing bitter tastes may be adaptive because:

• Different toxins may produce different bitter signals.

• Fine discrimination could prevent poisoning.

This provides biological plausibility for the explanation.

Limitation: learning and culture shape preferences

Food preferences vary considerably between cultures.

People learn to enjoy tastes that may initially be disliked, including strongly flavoured or bitter foods.

This creates a challenge to a purely evolutionary account.

If preferences were determined only by inherited biology, substantial cultural differences would be difficult to explain.

AQA mark schemes identify cultural learning and exposure to foods such as chilli as important competing influences.

Interactionist conclusion

Cultural variation does not necessarily disprove evolved predispositions.

People may inherit:

• A broad preference for energy-rich food.

• A cautious response to bitterness.

Culture determines:

• Which foods provide those tastes.

• How they are prepared.

• Whether repeated exposure changes acceptance.

• Which foods are considered desirable.

Limitation: individual differences

People vary in:

• Sensitivity to bitterness.

• Enjoyment of sweetness.

• Willingness to try unfamiliar foods.

• Strength of learned aversions.

AQA identifies genetically based individual differences in bitterness sensitivity as a challenge to a universal evolutionary account.

Interpretation

Individual differences may show that:

• There is no single identical preference shared by everyone.

• Several genetic variants may be involved.

• Learning and culture modify predispositions.

However, evolutionary explanations do not require every person to behave identically.

Natural selection operates on population tendencies, while variation remains.

Limitation: the explanation may better account for avoidance than precise preferences

Taste-aversion research provides strong evidence that organisms avoid foods associated with illness.

It does not automatically explain why a person prefers:

• One sweet food over another.

• A particular cuisine.

• A food linked with family celebrations.

• A brand advertised by a celebrity.

AQA’s 2021 mark scheme notes that classical conditioning may explain aversions more successfully than preferences.

Detailed food choices often require learning and cultural explanations.

Limitation: modern preferences can be maladaptive

Strong attraction to sugar and fat can contribute to excessive energy intake in modern environments.

This appears inconsistent with the claim that evolutionary tendencies are beneficial.

Response

Natural selection favoured behaviour that improved success in ancestral environments.

It does not guarantee health in every future environment.

A preference can be:

• Historically adaptive.

• Currently mismatched.

This makes evolutionary mismatch an explanation of the apparent contradiction rather than a complete rejection of the theory.

Limitation: not every bitter food is dangerous

Some bitter foods are safe or beneficial.

A complete system of bitterness avoidance could therefore cause people to reject nutritious food.

AQA’s taste-aversion mark scheme recognises that the role of bitterness is complicated because some bitter foods may have protective health effects.

Explanation

An evolved tendency does not have to be perfectly accurate.

A cautious system can still improve survival overall even if it sometimes produces false alarms.

Learning enables people to distinguish:

• Dangerous bitter foods.

• Safe bitter foods.

Limitation: non-human animal research

Much evidence for taste aversion comes from:

• Rats.

• Wolves.

• Coyotes.

Strength

Animal studies allow researchers to:

• Control food exposure.

• Manipulate the consequences of eating.

• Measure avoidance directly.

• Investigate survival-relevant learning.

Limitation

Humans have additional influences involving:

• Language.

• Cultural knowledge.

• Dietary rules.

• Advertising.

• Conscious expectations.

Animal findings support basic biological mechanisms but cannot explain the complete complexity of human food choice.

Reductionism

Evolutionary explanations can be biologically reductionist because they explain complex food choices through:

• Inherited predispositions.

• Taste receptors.

• Adaptive survival mechanisms.

This produces clear and testable ideas.

However, it can overlook:

• Family habits.

• Social identity.

• Religion.

• Culture.

• Economic access.

• Advertising.

• Individual experience.

A preference for one particular meal cannot always be reduced to its sweetness, fat or salt content.

Determinism

An evolutionary explanation may appear biologically deterministic because it suggests that inherited adaptations guide food preference.

However, behaviour is not inevitable.

People can:

• Learn to tolerate new foods.

• Develop new preferences.

• Reject foods they once liked.

• Follow cultural or ethical diets.

• Deliberately limit energy-rich foods.

The better conclusion is probabilistic:

Evolution creates biases, while experience and choice influence how those biases are expressed.

Practical applications

Encouraging dietary variety

Understanding neophobia suggests that rejection of a new food does not always mean permanent dislike.

Repeated safe exposure may:

• Increase familiarity.

• Reduce perceived danger.

• Expand dietary variety.

Avoiding accidental conditioned aversion

Where possible, distinctive favourite foods may be kept separate from experiences likely to produce severe nausea.

This follows from human evidence showing that a food paired with treatment-related sickness can become aversive.

Understanding children’s choices

Parents may recognise that:

• Attraction to sweetness can have an evolutionary basis.

• Initial rejection of a new vegetable can reflect neophobia.

• Hostile pressure is not necessarily the best response.

• Modelling and exposure can modify inherited tendencies.

The learning processes are examined in how parents and cultures shape food preferences [Learning and food preferences].

Applying evolutionary explanations in examinations

Step 1: identify approach or avoidance

Is the person:

• Seeking a particular food?

• Rejecting an unfamiliar food?

• Avoiding a food associated with sickness?

Step 2: identify the adaptive problem

Ask what ancestral danger or need the tendency may have addressed.

Examples:

• Energy shortage.

• Nutrient need.

• Poisoning.

• Unfamiliar plants.

• Repeated illness.

Step 3: explain survival value

Do not stop at:

“Humans evolved to like sugar.”

Develop the point:

“Sweetness signals a source of rapidly available energy. Individuals attracted to energy-rich food would have been more likely to survive periods of scarcity and pass on the associated predisposition.”

Step 4: apply the exact scenario detail

Use the food or behaviour named in the question.

Step 5: use cautious language

Use:

• “May reflect.”

• “Could have increased survival.”

• “Is consistent with.”

• “Provides an inherited predisposition.”

Avoid:

• “Every person.”

• “Genes force people.”

• “The preference is entirely innate.”

• “The behaviour proves evolution.”

Application example: sweetness and neophobia

A six-year-old eats sweet foods such as peas and biscuits but spits out every unfamiliar food.

A developed application would state:

• Sweet foods provide readily available energy.

• A preference for sweetness may therefore have had ancestral survival value.

• Spitting out unfamiliar food demonstrates neophobia.

• Caution towards new substances could have protected children from poisoning.

• Learning and repeated safe exposure may later change the preference.

This reflects the food-preference application used in AQA’s 2021 assessment.

Application example: taste aversion

Amelie previously enjoyed vanilla ice cream. She ate it before a medical treatment that caused severe nausea and now refuses vanilla ice cream.

A developed explanation would state:

• The food is familiar, so this is not neophobia.

• The flavour became associated with nausea.

• Amelie developed a learned taste aversion.

• Being prepared to avoid food associated with illness would have protected ancestral humans from repeated poisoning.

Application example: bitterness

A toddler tastes an unfamiliar sprout, makes a disgusted expression and refuses to eat any more.

Two processes may apply:

• The initial hesitation towards the unfamiliar sprout demonstrates neophobia.

• Rejection following its bitter taste demonstrates taste aversion.

• Bitterness may function as a signal of possible toxicity.

A strong answer distinguishes the components rather than applying one label vaguely.

Application example: fatty food

A child consistently chooses high-fat food when several familiar meals are available.

An evolutionary explanation would suggest:

• Fat provides concentrated energy.

• In ancestral environments, selecting calorie-dense food could protect against future scarcity.

• The attraction may therefore reflect an evolved preference.

• Modern availability and learning will also influence the precise choice.

How to structure a four-mark difference question

The June 2024 paper asked students to use an example of each and explain the difference between neophobia and taste aversion. The mark scheme awarded:

• One mark for a valid neophobia example.

• One mark for a valid taste-aversion example.

• Two marks for a clear explanation of the difference.

A full-mark answer could be:

“Neophobia is an innate avoidance of new or unfamiliar foods, such as a baby refusing a vegetable they have never encountered. Taste aversion is avoidance of a particular flavour associated with danger or illness, such as refusing ice cream after it was followed by chemotherapy-related nausea. Neophobia is therefore based on unfamiliarity, whereas taste aversion is based on toxicity, bitterness or a harmful experience.”

How to structure an evolutionary paragraph

Use:

Preference or avoidance: Identify the behaviour.Adaptive problem: State the ancestral challenge.Survival benefit: Explain how the behaviour helped.Selection: Explain why the tendency became more common.Application: Connect it to the example.

Model paragraph

“A preference for sweet foods may be an evolved adaptation. Sweetness often indicates carbohydrates, which provide rapidly available energy. In ancestral environments where food supply was uncertain, individuals attracted to these foods may have been more likely to survive and reproduce. The biological predisposition would therefore become more common through natural selection. This could explain why the child in the scenario chooses sweet peas and biscuits.”

Overall conclusion

Evolutionary explanations propose that food preferences reflect adaptations to recurring ancestral problems.

Preferences for:

• Sweetness.

• Fat.

• Salt.

may have encouraged the intake of energy and essential nutrients.

Avoidance mechanisms provided protection against danger:

• Neophobia involves innate caution towards new and unfamiliar food.

• Taste aversion involves avoidance of flavours linked with toxicity, bitterness or illness.

The explanation is supported by:

• The survival value of the preferences.

• Specialised taste systems.

• Animal research.

• Human evidence of conditioned taste aversion.

However, food choice is not entirely inherited.

Preferences vary through:

• Individual sensitivity.

• Learning.

• Repeated exposure.

• Family modelling.

• Cultural practices.

• Modern food availability.

The most balanced conclusion is that evolution supplies broad approach and avoidance biases, while learning and culture shape the particular foods people ultimately prefer.

Key Words 🔑

Key word	Student-friendly definition	How it may be used in an exam
Food preference	Tendency to select, enjoy or avoid a particular food or flavour	Introduce the behaviour being explained
Evolutionary explanation	Account proposing that behaviour developed because it increased survival or reproduction	Explain food preferences
Evolution	Change in inherited characteristics across generations	Explain how adaptations become common
Natural selection	Process favouring inherited characteristics that improve reproductive success	Explain the development of preferences
Adaptation	Characteristic shaped because it solved a recurring survival or reproductive problem	Describe sweet or bitter preferences
Selection pressure	Environmental challenge affecting survival and reproduction	Explain scarcity or poisoning
Reproductive success	Success in passing genes to future generations	Explain why adaptive tendencies spread
Inherited predisposition	Biological tendency passed between generations	Avoid saying behaviour is inevitable
Ancestral environment	Environment in which human adaptations developed	Explain the original survival benefit
Evolutionary mismatch	Earlier adaptation producing different consequences in a changed environment	Evaluate modern high-calorie diets
Energy-rich food	Food providing a high level of usable energy	Explain sweet and fatty preferences
Sweetness	Taste commonly associated with carbohydrate and energy	Apply preference for sugar
Bitterness	Taste that can signal possible toxicity	Explain avoidance
Taste receptor	Sensory receptor detecting a particular taste quality	Support biological preparedness
Neophobia	Innate fear or avoidance of new and unfamiliar food	Apply refusal of a novel food
Novel food	Food not previously encountered	Identify a neophobia example
Taste aversion	Avoidance of a flavour linked with bitterness, toxicity or illness	Apply food avoidance after nausea
Conditioned taste aversion	Learned avoidance after a food is associated with illness	Explain the Garcia effect
Garcia effect	Prepared tendency to associate a food’s taste with later sickness	Link evolution and learning
Biological preparedness	Inherited readiness to form some associations more easily than others	Evaluate taste-aversion evidence
Innate	Present without requiring a particular personal learning experience	Explain neophobia or bitter avoidance
Learned aversion	Avoidance acquired through experience	Apply illness followed by food refusal
Toxicity	Capacity of a substance to cause harm or poisoning	Explain avoidance mechanisms
Classical conditioning	Learning through association between events	Explain conditioned taste aversion
Stimulus	Event or object capable of producing a response	Describe food and illness associations
Avoidance	Behaviour preventing contact with a particular food	Explain survival value
Generalisation	Applying findings from one group or species to another	Evaluate animal research
Individual difference	Variation between people	Evaluate bitterness sensitivity
Cultural influence	Effect of shared social practices on food choice	Contrast evolutionary explanations
Reductionism	Explaining complex food choices through a limited number of biological mechanisms	Evaluate explanatory scope
Biological determinism	View that inherited biology controls behaviour	Evaluate flexibility of preferences
Interactionism	View that inherited predispositions and experience work together	Reach a balanced conclusion

Hints from the Examiner Reports 💡

Examiner hint: Do not reverse neophobia and taste aversion.

The June 2024 examiner report found that some students confused the two definitions.

Remember:

• Neophobia: newness.

• Taste aversion: danger or illness.

Examiner hint: Give a genuine example, not a repeated definition.

The 2024 examiner report noted that students often repeated the definition rather than providing a specific example, particularly for neophobia.

Weak:

“A person avoids unfamiliar food.”

Stronger:

“A baby refuses a new vegetable that has never been offered before.”

Examiner hint: The food must be specific.

AQA’s 2024 mark scheme required:

• A particular unfamiliar food for neophobia.

• A particular food associated with illness, toxicity or bitterness for taste aversion.

Examiner hint: State why the concepts differ.

Examples alone are not enough for a question asking for the difference.

Use:

“Neophobia is caused by unfamiliarity, whereas taste aversion is based on a danger signal or illness association.”

Examiner hint: Keep an evolutionary explanation focused on survival.

Do not merely write:

“People like sweet food because it tastes nice.”

Explain:

sweetness → energy → survival advantage → natural selection

Examiner hint: Apply every part of a scenario separately.

In the 2021 Arya and Neela scenario:

• Sweet peas and biscuits could be linked with rapid energy.

• Rejection of new food could be linked with neophobia.

• Roast dinners could be linked with high energy from fat.

• Family eating could be linked with learning rather than evolution.

Examiner hint: Do not treat all food preferences as innate.

Use learning and culture as evaluation, then reach an interactionist conclusion.

Examiner hint: Explain what taste-aversion research shows.

Do not write only:

“Garcia supports the theory.”

Explain that organisms preferentially associate taste with sickness, indicating biological preparedness for an adaptive association.

Examiner hint: Be careful with bitterness.

Bitterness may signal toxicity, but not every bitter food is harmful. This makes avoidance protective but imperfect.

Examiner hint: When evaluating animal research, connect the limitation to the explanation.

Weak:

“Rats are different from humans.”

Stronger:

“Human preferences are shaped by language and culture, so a rat’s conditioned avoidance may demonstrate a basic mechanism without explaining complex human meal choices.”

Common Mistakes ⚠️

Mistake: Saying evolution means people consciously chose useful foods

Why this is incorrect:

Evolution occurs across generations rather than through deliberate planning.

How to improve:

Explain inherited variation and natural selection.

Mistake: Saying individuals evolve during their lifetime

Why this is incorrect:

Populations change across generations.

How to improve:

State that adaptive predispositions become more common through reproduction.

Mistake: Saying humans evolved because they needed a preference

Why this is inaccurate:

Evolution does not plan characteristics according to future need.

How to improve:

Explain that existing variation was selected where it improved survival.

Mistake: Saying preferences guarantee survival

Why this is too strong:

An adaptation only changes probability.

How to improve:

Use terms such as “increased the likelihood” or “provided an advantage”.

Mistake: Saying sweet food is preferred only because it is enjoyable

Why this is incomplete:

The evolutionary explanation requires survival value.

How to improve:

Link sweetness with rapidly available energy.

Mistake: Saying fat is preferred because it is unhealthy

Why this is incorrect:

The explanation concerns its concentrated energy value.

How to improve:

Refer to ancestral scarcity and energy storage.

Mistake: Saying bitterness always proves that food is poisonous

Why this is incorrect:

Some bitter foods are safe or beneficial.

How to improve:

Describe bitterness as a possible danger signal.

Mistake: Defining neophobia as fear of all food

Why this is incorrect:

It specifically concerns new or unfamiliar food.

How to improve:

Include unfamiliarity in the definition.

Mistake: Saying neophobia develops after food poisoning

Why this is incorrect:

That describes taste aversion.

How to improve:

Remember that neophobia occurs before the unfamiliar food has been safely experienced.

Mistake: Giving an example involving a familiar food for neophobia

Why this is incorrect:

Familiarity rules out the central feature.

How to improve:

State clearly that the food has never been encountered before.

Mistake: Defining taste aversion as dislike of every new food

Why this is incorrect:

That is neophobia.

How to improve:

Link taste aversion with danger, bitterness or illness.

Mistake: Assuming taste aversion must be innate

Why this is incorrect:

It may also be conditioned after illness.

How to improve:

Distinguish innate bitter avoidance from learned food aversion.

Mistake: Assuming taste aversion must involve a genuinely poisonous food

Why this is incorrect:

The food can become associated with nausea even where it did not cause the illness.

How to improve:

Explain the association between flavour and sickness.

Mistake: Saying neophobia and taste aversion are the same because both involve avoidance

Why this is incomplete:

The cause of the avoidance differs.

How to improve:

Contrast newness with harmful association.

Mistake: Describing classical conditioning without evolutionary relevance

Why this loses focus:

The lesson concerns evolutionary explanations.

How to improve:

Explain that organisms are biologically prepared to connect taste and illness because the association aided survival.

Mistake: Naming Garcia without describing the finding

Why this is incomplete:

A study name alone does not demonstrate understanding.

How to improve:

State the food, illness pairing and later avoidance.

Mistake: Saying animal evidence proves human preference

Why this is too strong:

Humans experience cultural and cognitive influences not captured by animal research.

How to improve:

Describe the evidence as support for a basic mechanism.

Mistake: Treating modern health risks as proof that evolution is wrong

Why this is simplistic:

Adaptations developed under different environmental conditions.

How to improve:

Use evolutionary mismatch.

Mistake: Ignoring learning and culture during evaluation

Why this weakens the answer:

Specific food preferences vary considerably.

How to improve:

Conclude that inherited biases are modified by experience.

Exam-Style Questions ✍️

Questions

1. What is meant by a food preference?[2 marks]

2. Explain how natural selection may have produced human food preferences.[4 marks]

3. Explain why a preference for sweet food may have evolutionary value.[3 marks]

4. Explain why a preference for fatty food may have been adaptive.[3 marks]

5. What is meant by food neophobia?[2 marks]

6. What is meant by taste aversion?[2 marks]

7. Using an example of each, explain the difference between neophobia and taste aversion.[4 marks]

8. Theo happily eats familiar carrots but refuses to try an unfamiliar purple vegetable.

Explain Theo’s behaviour using an evolutionary explanation.[4 marks]

9. Laila previously enjoyed coconut ice cream. She ate it immediately before becoming severely ill and now feels sick whenever coconut ice cream is offered.

Explain Laila’s behaviour.[4 marks]

10. A young child prefers sweet biscuits, avoids new vegetables and rejects a bitter sprout after tasting it.

Explain these three behaviours using evolutionary explanations of food preference.[6 marks]

11. Briefly outline and evaluate one study of taste aversion.[4 marks]

12. Explain one strength and one limitation of the evolutionary explanation of food preferences.[6 marks]

13. Compare neophobia and taste aversion.[6 marks]

14. Evaluate evolutionary explanations of food preferences.[8 marks]

15. Discuss evolutionary explanations of food preferences. Refer to the following scenario in your answer.

Milo prefers sweet and fatty foods. He refuses to taste any unfamiliar vegetables. Last year, Milo became ill shortly after eating fish and has avoided fish ever since. His parents regularly eat strongly flavoured foods that Milo initially rejected, but he has gradually started eating some of them.

[16 marks]

Answers and Mark Scheme

Question 1

Award up to two marks:

• A food preference is a tendency to select, enjoy or avoid a particular food.

• It may involve attraction to or rejection of a taste or flavour.

Question 2

Award up to four marks:

• Individuals in ancestral populations varied in their food preferences.

• Some preferences improved survival, for example selecting energy-rich foods or avoiding toxins.

• Individuals possessing those tendencies were more likely to survive and reproduce.

• They passed associated inherited characteristics to their offspring.

• The adaptive predispositions became increasingly common over generations.

Question 3

Award up to three marks:

• Sweetness is commonly associated with carbohydrate or sugar.

• These provide readily available energy.

• Energy supported survival, movement and reproduction in environments where food was uncertain.

• Attraction to sweetness could therefore have been favoured by natural selection.

Question 4

Award up to three marks:

• Fat is energy dense.

• Consuming fatty foods provided concentrated calories.

• Stored energy could protect against later food scarcity.

• Individuals preferring such foods may have had a survival advantage.

Question 5

Award up to two marks:

• Neophobia is an innate fear, dislike or avoidance.

• It concerns new or unfamiliar foods.

Question 6

Award up to two marks:

• Taste aversion is avoidance or dislike of a particular food or flavour.

• The avoidance is connected with bitterness, toxicity or association with illness.

• It may be innate or learned.

Question 7

Award up to four marks:

• Neophobia concerns avoidance because a food is new.

• For example, a baby refuses an unfamiliar vegetable without tasting it.

• Taste aversion concerns avoidance because a food signals danger or has been associated with illness.

• For example, a person refuses ice cream after eating it before nausea-inducing treatment.

• The difference is therefore unfamiliarity compared with danger, toxicity or illness association.

This reflects the distinction assessed by AQA in June 2024.

Question 8

Award up to four marks:

• Theo already eats carrots, showing that vegetables in general are not necessarily disliked.

• The purple vegetable is unfamiliar.

• His refusal therefore demonstrates neophobia.

• Innate caution towards new foods may have protected ancestral children from poisonous substances.

• This tendency may have been favoured through natural selection.

Question 9

Award up to four marks:

• Coconut ice cream was initially familiar and liked.

• It was experienced shortly before severe illness.

• Laila formed a learned taste aversion.

• The flavour now produces nausea or avoidance.

• An inherited readiness to avoid food associated with sickness would have reduced repeated poisoning.

Question 10

Award up to six marks:

• Sweet biscuits provide rapidly available energy.

• A preference for sweetness may therefore have offered ancestral survival value.

• Avoidance of unfamiliar vegetables demonstrates neophobia.

• Neophobia protected children from eating unknown poisonous foods.

• Rejection of the sprout after tasting bitterness demonstrates taste aversion.

• Bitterness may signal toxicity.

• These tendencies could become common through natural selection.

Question 11

Award up to two marks for outline and two for evaluation.

Possible study: Garcia and Koelling

• Rats developed an aversion to sweet water after it was paired with poison-induced illness.

• The same association did not develop in the same way when the flavour was paired with electric shock.

• This supports biological preparedness because taste is selectively associated with internal sickness.

• However, rats differ from humans, whose food preferences are strongly influenced by culture and cognition.

Possible study: Bernstein and Webster

• Adults receiving nausea-inducing chemotherapy developed an aversion to ice cream associated with treatment.

• This demonstrates conditioned taste aversion in humans.

• However, chemotherapy is an unusual context, so findings may not generalise to everyday food preference.

Other valid studies may receive credit.

Question 12

Award up to three marks for a developed strength and three for a developed limitation.

Possible strength:

Taste-aversion research supports biological preparedness. Rats more readily associated a taste with sickness than with electric shock, which is adaptive because taste is a useful predictor of poisoning.

Possible limitation:

Human preferences vary substantially between cultures. People learn to enjoy foods initially considered bitter or unpleasant, showing that inherited predispositions cannot explain specific preferences by themselves.

Alternative creditworthy points include:

• Infant evidence.

• Specialised taste receptors.

• Individual differences.

• Animal generalisation.

• Evolutionary mismatch.

• Modern availability of energy-rich food.

Question 13

A strong answer may include:

• Both involve food avoidance.

• Both may increase survival by reducing poisoning risk.

• Neophobia concerns unfamiliar foods.

• Taste aversion concerns foods associated with danger, bitterness or illness.

• Neophobia is generally described as innate.

• Taste aversion may be innate or learned.

• Neophobia often occurs before tasting the food.

• Learned taste aversion follows an experience involving illness.

• Neophobia is often associated with young children.

• Taste aversion can occur at any age.

• A new vegetable refusal is neophobia.

• Ice-cream avoidance after nausea is taste aversion.

Higher marks require direct comparison rather than two isolated definitions.

Question 14

A strong answer should include developed evaluation such as:

• Sweet and fatty preferences have clear ancestral survival value.

• Avoidance of bitterness may reduce poisoning.

• Neophobia protects children before unfamiliar foods are tested.

• Taste aversion prevents repeated consumption of apparently harmful food.

• Garcia’s research supports biological preparedness.

• Human chemotherapy evidence supports conditioned taste aversion.

• Animal studies may not generalise fully to human food choice.

• Cultural and social learning produce major differences in preference.

• Individual differences exist in bitterness sensitivity.

• Taste-aversion evidence may explain avoidance more successfully than positive preference.

• Modern energy-rich environments create evolutionary mismatch.

• The account can be biologically reductionist.

• An interactionist explanation combining evolved biases with learning is more complete.

Question 15

A strong response should include:

Knowledge and understanding

• Evolutionary explanation of food preference.

• Natural selection.

• Adaptation.

• Survival and reproductive value.

• Preference for sweet food.

• Preference for fatty food.

• Avoidance of bitterness.

• Neophobia.

• Taste aversion.

• Biological preparedness.

• Conditioned taste aversion.

• Possible evolutionary mismatch.

Application

• Milo’s sweet preference may reflect attraction to rapidly available energy.

• His fatty-food preference may reflect attraction to concentrated calories.

• Both tendencies could have improved survival during ancestral scarcity.

• Refusal of unfamiliar vegetables demonstrates neophobia.

• Neophobia may have protected ancestral children from unknown poisonous foods.

• Milo’s fish avoidance is not neophobia because fish was previously eaten.

• Illness after eating fish produced a learned taste aversion.

• Avoiding fish may reflect preparedness to associate food with sickness.

• Gradually eating strongly flavoured foods demonstrates that exposure and social learning can modify initial avoidance.

• His parents may act as models, which links with learning explanations.

Evaluation

• Food approach and avoidance have clear adaptive value.

• Taste receptors provide biological plausibility.

• Garcia and Koelling support selective preparedness.

• Human taste-aversion evidence reduces reliance on animal studies.

• Animal findings cannot explain every complex human preference.

• Culture and family practices alter preferences.

• Individual differences challenge a universal account.

• Modern availability of sugar and fat can make ancestral preferences maladaptive.

• Not all bitter foods are dangerous.

• Evolution may explain broad flavour biases better than preferences for particular meals.

• The account may be biologically reductionist.

• Evolutionary tendencies are probabilistic rather than completely deterministic.

• An interactionist explanation involving evolution, exposure and modelling is most complete.

Higher-level responses will distinguish neophobia from taste aversion precisely, connect each behaviour in the scenario with its adaptive function and evaluate the evolutionary account without treating learning and biology as mutually exclusive.