Examine one evolutionary explanation of behaviour

Question 1

What theory did Charles Darwin suggest? What assumption is it based on? (2)

Answer 1

• theory of evolution
• based on the assumption that living organisms face environmental challenges and that the organisms that adapt the best have a greater chance of passing on their genes to the next generation

Question 2

Organisms with what are said to be what? How important is this process in Darwin’s theory? (3)

Answer 2

• specific genetic traits
• naturally selected
• natural selection is a crucial evolutionary process

Question 3

Name one evolutionary explanation of behaviour. (1)

Answer 3

• disgust in pregnant women

Question 4

What occurs during pregnancy? Why might females have evolved this way? (2)

Answer 4

• nausea and loss of appetite

- as a way to protect the mother and the fetus against diseases which could threaten the fetus

Question 5

What is the theory under investigation? (1)

Answer 5

• is whether disgust has evolved to compensate for the mother and the baby’s vulnerability to disease during the first few months of pregnancy

Question 6

Name a study that tests an evolutionary explanation of behaviour. (1)

Answer 6

• Fessler et al. (2005) Elevated disgust sensitivity in the first trimester of pregnancy

Question 7

Aim: Fessler et al. (2005) Elevated disgust sensitivity in the first trimester of pregnancy (1)

Answer 7

Aim: To investigate if disgust sensitivity in the first trimester of pregnancy was elevated as predicted

Question 8

Method: Fessler et al. (2005) Elevated disgust sensitivity in the first trimester of pregnancy (6+8)

Answer 8

• web-based survey completed by 691 women recruited through pregnancy-related Web sites
• no compensation was offered for participation
• women’s mean age was 28.1 years
• web-based questionnaire, participants
  (1) indicated their current level of nauseasusing a 16-point scale
  (2) answered questions to test their disgust sensitivity in eight different areas;
• -food
• -contact with animals
• -body products
• -dead animals
• -hygiene
• -contact with toilets

Question 9

Findings: Fessler et al. (2005) Elevated disgust sensitivity in the first trimester of pregnancy (3)

Answer 9

• overall, disgust sensitivity related to food and body products in women in the first rimester was higher compared to those in the second and third trimester
• disgust was particularly elevated in relation to food = what the researchers predicted
• food-borne diseases = particularly dangerous to women in first trimester and therefore it was predicted that disgust sensitivity related to food = high = supported by results

Question 10

Conclusion:Fessler et al. (2005) Elevated disgust sensitivity in the first trimester of pregnancy (1)

Answer 10

• results may indicate that nausea and vomiting = evolved behaviour because they limit the likelihood that pregnant women will eat a dangerous food

Question 11

Evaluation: Fessler et al. (2005) Elevated disgust sensitivity in the first trimester of pregnancy (5)

Answer 11

• data collected through questionnaire = self-report may not be reliable
• not an effective way of measuring disgust
• would have been more reliable to confront participants with real disgust-eliciting objects
• effect sizes = not big but significant
• findings supported by other studies (Curtiss et al. 2004) = that images that threaten the immune system are judged as more disgusting

Question 12

Evaluation of evolutionary explanations (3)

Answer 12

• difficult to test evolutionary theories + not much is known about early life of humans
• evolutionary explanations tend to focus on biological factors and underestimate cultural influences
• according to Davey (1974) disgust for spiders may be explained by people’s need to find tangible causes of illness and disease when causes unclear

Question 13

Examine one evolutionary explanation of behaviour

Answer 13

• theory of evolution (2)
• nausea (2)
• fessler (23)
• evaluation of evolutionary explanations (3)