Evolutionary Explanations for Food Preference Flashcards
What does the theory believe?
That adaptive behaviour improves chances to survive and is inherited. This has also affected our food preferences. Since a varied diet which is high in energy and key nutrients and avoids toxic foods aids our survival, such preference has become genetically bred into us.
What are the two reasons why preference for sweet foods is adaptive?
- Sweet things have high calorie content and high in energy. The sweet taste is an easy-detectable signal of nutrients and easily accessible source of energy
- Sweet things are rarely poisonous. Sweet taste = signals safety
In evolutionary terms, what happens to those with preference for sweet taste?
In evolutionary terms, those with preference for sweet taste means they are more likely to survive and pass on the genes of the preference for sweet which becomes genetically bred into the population.
Why is preference for meat adaptive?
- Meat is packed w high proportion of calories and a large amount of energy
- Contains amino acids, minerals and protein which helped supplement the low-calorie diet of ancestors, giving them a wider variety of nutrients and more balanced diet
- Meat improves chances of survival - therefore the gene coding for meat preference is passed on and genetically bred into the population due to its adaptive value, therefore preference for meat is still present today.
Why is taste aversion adaptive?
- Bitter and sour foods are more likely to be toxic verses other tastes which leads to natural taste aversion to such food - genetically bred into humans
- Helps us quickly avoid and naturally refrain from eating such food which improves chance of survival
- Also have an inherited ability to rapidly form future taste aversions to food which makes us sick - prevents us re-consuming anything which makes us ill and reduces chances of survival, e.g. Garcia et al: rats made ill through radiation after overconsuming saccharin - developed aversion to it
Study on taste aversion:
Garcia and Koelling: rats developed taste aversion to sweet water flavoured with saccharine after pairing it with radiation that made them ill. Furthermore, the same effect did not occur when pairing sweet water with electric shocks.
- while this is based on learning, the ability of our body to form a reflex sickening feeling to anything which made us ill is evolutionary acquired.
What is food neophobia?
A general fear of experiencing new food which may be unfamiliar to us
Why is food neophobia adaptive?
This is adaptive (improves chances of survival) as means less likely to consume new substances which could be toxic / poisonous. - this protects us from harm / illness / death caused by such food.
- aids survival and is passed on through evolution
Research on neophobia:
Dovery et al: individuals have expectation of how food should look and smell. Unfamiliar food that does not fall in this catagory is rejected.
A strength of evolutionary explanations of food preferences is there is research support.
Steiner: facial expressions of new born babies indicate pleasure and acceptance to sweet taste + rejection and disgust to bitter taste. Shows that: evolutionary processes influence taste preferences. Infants lack experience to learn preference but still avoid bitter taste which signal harmful substances in nature but accept sweet tastes which signal safety.
+ also physiological research support - human tongue has specific receptors for sweet flavour and more receptors for detecting sweet vs other tastes.
Supports the idea that sweet taste is more important to the body than other tastes + preference for sweet is driven by genetic and evolutionary factors
Weakness of evolutionary explanations of food preferences is there are individual differences in taste aversions.
Research from Drewnoski has found there is a genetic variation among humans in their ability to detect a bitter chemical in food called PROP. Hence, people differ in their ability to taste bitter chemicals in food. Some people cannot taste bitter-tasting chemicals (non-tasters) whilst others are very sensitive to it (supertasters) and avoid food containing any bitter tasting chemicals. This refutes the evolutionary explanation as according to the theory, tasting bitter flavours is essential to survival and thus should be bred into everyone (universal trait). As this is not the case, poses problems for the explanation, decreasing it in validity.
Weakness of evolutionary explanations of food preferences is that there is refuting evidence for the idea that neophobia is adaptive. Although neophobia has adaptive benefits, it also leads to inadequate nutritional practises.
E.g. an Australian study (Perry et al) found that neophobia is associated with poorer dietary quality among children. WB: it shows that in our modern food environment, having a neophobia restricts the variety of children’s diet and limits what they eat which could lead to health problems e.g. deficiencies which contradicts the idea that assertion increases chance of survival. Decrease in validity.
Weakness of evolutionary explanation is that it is deterministic bc it proposes that eating behaviour is controlled by evolutionary factors such as which food preferences may be adaptive.
It therefore ignores free will and the fact that our decisions of what we eat is affected by our conscious choices. For example, people with health concerns, e.g. diabetes, choose to avoid sugary foods despite the evolutionary urge to eat sweet flavours. Also vegans and vegetarians use free will to avoid eating meat despite its adaptive benefit and our preference for meat. As a result, the explanation offers a negative outlook on eating behaviour which is fixed and fails to acknowledge that humans make choices about what they eat.
