Evolutionary explanations of food preference Flashcards
Evolutionary explanation
-The explanation of food preference established how humans have evolved to have certain food preferences in order to aid our survival.
Aiding survival
-If the genes aided the survival they would be more likely to stay in the gene pool.
Environment of Evolutionary Adaptiveness
Human kind evolved in the ancestral environment, when humans lived in hunter gather communities, so the food preferences were adapted for the that environment. So today where the food in plentiful they are no longer in use but remain with us a ‘evolutionary hangovers’
Preference for sweet food
-We are encouraged to eat sweet foods because they contain fructose which provides calories needed for energy for survival processes like ‘fight or flight’.
Preference for salt
-Its essential to maintain sodium balance for bodily function. It was scarce in the wild and so this may have encouraged ancestors to eat meat which is rich in protein
Fatty foods preference
-Similarly the high fat foods were not readily available and they are a good source of energy and so humans who preferred fatty foods after brief exposure were more likely to survive
Tendency to eat impulsively
-This tendency to eat impulsively or ‘binge eat’ became particularly adaptive as humans migrated towards the northern hemisphere in harsh weather conditions where food is less readily available
Familiarity in foods
-We prefer foods which are more familiar to us, we have a tendency to avoid foods which are unfamiliar to us (neophobia) which has evolved to stop us eating foods which could have been poisonous
Taste aversion learning
We also avoid foods which have made us sick in the past, so we are innately ‘primed’ to learn to link taste and nausea. This ability evolved to protect us from poisonous foods.
Desor et al. (1973)
- Found that using facial expressions and sucking behaviour as an indicator of preference, that 1 to 3 day old infants preferred sweet over non-sweet fluids.
- This supports the explanation because the infants haven’t had enough time to learn their own food preferences so this implies that there is an innate genetic preference for sweet foods.
Bell et al. (1973)
- They gave sweet foods to Eskimos of northern Alaska who had previously lacked sweet foods and drinks. They found that they did not reject the sugar containing food.
- This supports the explanation because they hadn’t learnt it from their culture so there must be an innate universal preference for sweet foods.
- Also they did not reject the foods so did not so any naturally occurring neophobic responses towards the sweet foods, must be genetic.
Garcia & Koelling (1966)
- Found that rats more easily learned to avoid drinking flavoured water when followed by illness (nausea) than by electric shock
- Because it was easier for the rats to make the association with nausea thus supports the idea of taste aversion learning by avoiding the foods that make us sick. This gene would then be passed on to offspring to give a survival advantage
- However weak generalisability because rats (although mammalian similarities)
Bernstein and Webster (Practical Application)
- Gave patients novel tasting ice cream before they received chemotherapy do they developed an aversion to that ice cream rather than normal or familiar foods.
- Beneficial as cancer patients undergoing chemotherapy are inevitably going to feel sick, so its more beneficial to make them associate this with a novelty food that they don’t normally eat than foods are beneficial to their health.
A further evolutionary idea is that humans have evolved an instinctive ability to select an optimal diet: supported by Davis (1928)
Davis (1928)
- Children living in a paediatric unit in the USA were offered a range of 10 to 12 healthy foods (without sugar, salt etc.) and were free to eat which ever. They found that the children were able to select a diet that was consistent wiht growth and health and no problems were observed in choosing those foods - highlights innate food preferences.
- Naturalistic yet controlled environment (so food choices would to some extent reflect their daily intake)
- Highlights existence of biological drives
- Demonstrates importance of the environment as the types of food were restricted to healthy ones
- Therefore (PA) if in real life children were restricted they may make healthier choices
Evaluation of Desor et al.
strength= limited extraneous variables such as environmental or social factors as children are too young to have learnt the behaviour therefore this gives the findings greater validity. However interpreting preference from facial expressions is subjective and could be easily misinterpreted. Therefore expressions observed may not necessarily imply a sweet preference.
