Evolutionary explanation for behaviour ERQ

Evolutionary psychology

That human behaviour has evolved through natural selection to enhance survival and reproductive success.

Survival behaviour example

Disgust — protects against disease (Curtis et al., 2004).

Reproductive behaviour example

Jealousy — differs between sexes due to reproductive threats (Buss et al., 1992).

Aim of Curtis et al. (2004)

To investigate whether disgust is an evolved response to disease threats.

Method used in Curtis et al.

Online survey with over 40,000 participants across 165 countries. The sample completed a web-based survey using 20 photo stimuli.
They were shown a variety of different images, and the images were organised in pairs. One image of each pair was of infectious/potentially harmful stimuli whereas the other was of non-infectious stimuli
For example, one pair contained an image of a plate of bodily fluids and an image of a plate of blue viscous liquid
Participants had to rank each image from 1-5 (1 being the most disgusting and 5 being the least disgusting)

Key findings in Curtis et al.

Disgust was strongest for disease-related images; women showed higher disgust; responses were consistent across cultures.

Conclusion of Curtis

Disgust is likely an evolved universal behaviour that protects against pathogens and is heightened during reproductive years.

Strength of Curtis et al.

Large, cross-cultural sample increases generalisability; supports universality of disgust as an evolved trait.

Replicable and reliable

Limitation of Curtis et al.

Self-report method may be subjective; lacks experimental control due to online format.

Aim of Buss et al. (1992)

To examine sex differences in jealousy in response to emotional vs. sexual infidelity.

Method used by Buss et al.

202 college students who were participants imagined emotional and adult infidelity scenarios and chose which was more distressing; physiological responses were also recorded such as sweat response

Findings in Buss et al.

60% of men (17% of women) were more distressed by the sexual infidelity scenarios and 83% of women (40% of men) were more distressed by the emotional infidelity scenario than the sexual one. Men showed more physiological activity in the sexual infidelity scenario compared with the emotional one. Women showed the opposite but the differences were not as strong as they were for men.

Conclusion of Buss

Jealousy evolved differently for men and women as an adaptive solution to reproductive challenges (paternal uncertainty vs. loss of resources).

Strength of Buss et al. (1992)

Combines self-report with physiological data; findings align with evolutionary theory and parental investment model.

Limitation of Buss et al. (1992)

Uses hypothetical scenarios; limited to U.S. college students; possible influence of cultural gender norms.

Behavioural suggestion from studies

That behaviours like disgust and jealousy may have evolved to solve survival and reproductive problems faced by our ancestors. However, both studies use hypothetical scenarios which may not accurately reflect real scenarios

Criticism of evolutionary explanations

They can be reductionist, overlooking cultural, emotional, and social influences on behaviour.

Conclusion of the ERQ

Evolutionary psychology explains important behaviours but should be integrated with other perspectives to fully understand human complexity.