BLOA - Examine one evolutionary explanation of behaviour

Question 1

Darwin’s theory of natural selection

Answer 1

5 main points:

• overpopulation + scarce resources = struggle to survive
• variations in individual traits due to mutations and meiosis (e.g. crossing over)
• better adapted traits = higher chance of survival
• more successful traits are favored by natural selection
• over time more successful traits become more prevalent in the population

Question 2

disgust in pregnant women

Answer 2

• nausea and loss of appetite during pregnancy may have an evolutionary basis
• disgust may be a food-rejection mechanism to prevent contamination and the spread of illness
• could be a way to protect the mother and fetus from diseases that could threaten the fetus

main study: Fessler et al. (2005)

Question 3

Fessler et al. (2005) - aim

Answer 3

to investigate if disgust sensitivity elevated during the first trimester of pregnancy

Question 4

Fessler et al. (2005) - process

Answer 4

1. 691 women completed a web-based survey through pregnancy-related sites
2. Participants were asked to:
   - indicate current levels of nausea (out of 16)
   - answer questions to test disgust sensitivity pertaining to 8 different areas (e.g. food, hygiene, etc)

Question 5

Fessler et al. (2005) - findings and conclusion

Answer 5

• disgust sensitivity related to food and body products higher with women in first trimester compared to other trimesters
• disgust particularly elevated in relation to food
• likely because food-borne diseases are particularly dangerous in the first trimester
• thus results indicate that disgust is evolved behaviour
• as it limits the likelihood that pregnant women will eat dangerous food

Question 6

Fessler et al. (2005) - evaluation

Answer 6

• data is empirically supported: Curtiss et al. (2004) also reported that images of objects threatening the immune system were judged as more disgusting
• unreliable: data was collected through questionnaires

Question 7

evolutionary assumptions that the behaviour supports

Answer 7

disgust aids survival as a form of protection against potential sources of disease

Question 8

evaluation of evolutionary explanations

Answer 8

• difficult to test evolutionary theories
• evolutionary explanations tend to undermine the significance of cultural influences
• Davey (1974): disgust for spiders may be explained by people’s need to find tangible causes of illness and disease when causes were unclear

Question 9

what to write when asked: “Examine one evolutionary explanation of behaviour”

Answer 9

• outline Darwin’s theory of natural selection
• distinguish individual components of the theory and discuss how they relate to one another
• “innate, naturally-selected traits benefit the individual” –
  explain using Fessler et al. (2005)
• discuss how specific research methods used to explore Darwin’s theory may influence the data gathered
• evaluate whether evolutionary explanations are credible + explain WITH EVIDENCE why you think so