Evolutionary Explanations of Food Preferences

Question 1

Spice

Answer 1

Chilli destroys bacteria = why hot countries use spice

Preserves meat in hot temps

Question 2

Cook

Answer 2

Chimps can’t cook = need strong jaw

We cook to break down food = easier to access nutrients

Our molers have shrunk in size because we don’t eat so many raw foods

Our brains grew as we learned to cook = massive advantage over others

Question 3

The Environment of Evolutionary Adaptation

Answer 3

Refers to the environment in which a species first evolved

Question 4

Genome lag

Answer 4

Some behaviour is not adaptive because genetic changes over thousands of generations have proceeded much slower than changes in our environment.

Tendency to gain weight because genes are programmed to cope with starvation not calorie excess

Question 5

Preference for meat

Answer 5

Fossil evidence from groups of hunter-gatherers = daily diet was derived from animal-based foods

Meat diet, full of densely packed nutrients provided catalyst for growth of brain

Without animals = unlikely humans would have secured enough nutrition to evolve into active + intelligent creatures

Meat = essential amino acids, mineral + nutrients early humans needed, allowing them to supplement with plants with lots of calories (rice + wheat)

Question 6

Bait shyness

Answer 6

Rats made ill through radiation after eating saccharin, developed an aversion to it + v.quickly associated their illness with saccharin

Hard to kill rats because they would take small amount of any new food + if became ill would learn to avoid it

Question 7

Adaptive advantages of taste aversion

Answer 7

Odour of food can be linked to illness + to development of food aversion

Helped ancestors because if were lucky enough to survive eating poisoned food = wouldn’t make same mistake again

Can still be acquired up to 24 hrs after consumption = reaction to poisoned food in natural environment is often delayed

Once learned aversions are hard to shift

Question 8

The Medicine effect

Answer 8

Any food being eaten before recovery from illness will be preferred in future

Garcia et al: When distinctive flavour is presented to thiamine deficient rat + then followed by injection of thiamine = animal will acquire preference to that flavour

Question 9

Importance of calories

Answer 9

Best way to predict which fruit + veg would be preferred by 4-5 yr olds = not how sweet but how dense they were in calories

Bananas + Potatoes = calorie rich + more likely to be chosen by children = evolved preference for calorie rich foods

Question 10

Could early humans have been vegetarians?

Answer 10

Anthropological evidence = all societies display preference for animal foods + fats

Not possible for early humans to be completely vegetarian because not able to get sufficient from plants + grains available

Question 11

Are all food preferences a product of evolution?

Answer 11

A trait that is beneficial today would not have evolved because of beneficial effects on ancestors e.g. consumption of low cholesterol foods

Many things important to ancestors, are harmful in modern environments = more likely to avoid them in order to survive + lead healthy life

Question 12

Sweet

Answer 12

Calories = energy

Breast milk = sweet

Question 13

Salt

Answer 13

Water balance = controls fluid balance

Needed for nerves to transmit

Question 14

Sour

Answer 14

High bacterial load = food gone off

Question 15

Bitter

Answer 15

High toxic chemicals

Babies naturally resist bitter veg

Question 16

Neophobia

Answer 16

Fear of new

Frost: children prefer familiar food

But humans like variety because need vitamins + minerals

Children preferred multi-coloured smarties

Question 17

Buss

Answer 17

Sex for meat = if brought back meat = get the women

Question 18

Stanford

Answer 18

Chimps eat fleshy fatty organs first = highest calorie content

Question 19

Real-World Application

Answer 19

Gave Chemo patients novel-tasting ice cream before treatment = p’s acquire aversion to it

Development of scapegoating technique = p form an aversion to the novel food + not to familiar usual food

Question 20

Testing Evolutionary Hypothesis

Answer 20

Modern-day human products = reflect our evolved food preferences

Sugary foods sell well because exploit evolved desires for fat, sugar etc

Question 21

Cultural differences

Answer 21

Innate responses do not account got broad range of food likes + dislikes that develop beyond infancy

Although evolved factors are clearly important in food selection, these are modified by our experience with different foods, culture determines such experiences