Sex differences Flashcards
What is the most evident sex difference between male and females?
The most evident sex difference is that males can opt out of parental investment in a way that females cannot. Through expending a large effort on courtship and mating, males in most species can afford to devote little in parental care. Human females need to invest more in response to adaptive pressures. As brain size increased this resulted in more difficult childbirths due to skull size increases. To compensate children are born relatively immature at 9 months compared to other animals. Females are therefore required to make a large investment pre-natal and post-natal. This is because females are required to care for the child during pregnancy for 9 months followed by years of care after in infancy. This investment is much higher in comparison to males who can invest a few moments of copulation and a teaspoonful of semen (Symons).
Why do males and females invest in their offspring to a different extent?
Evolutionists explain this difference due to females being certain of being the mothers of the children due to internal fertilization where as men do not have the same degree of certainty. This is made more difficult in more promiscuous mating arrangements where there is a risk of Cuckoldry. This results in a huge difference in the potential maximum reproductive success of each sex making random mating far too costly for human females. When males do invest in their children and females they are under pressure from protecting themselves from cuckoldry which is the risk of investing in children that are not their own. This is because males cannot be sure of paternity while females can. Due to this males have a greater concern about fidelity in their mating partners than their mates (Miller).
What did Buss et al. suggest?
Suggested that sexual jealousy may have evolved as a possible solution to this problem. Men are more jealous of the sexual act itself while women are jealous of the shift in emotional focus and the loss of resources and investment into another woman.
What would be the best strategy for women?
Infant dependency would mean females want male providers but also the expense of childrearing means females want to ensure good quality children too so their efforts are not wasted. One way to achieve this is to marry a man with good resources and who is caring yet “shop around” for men with good genes through extra-marital affairs with “studs” and attractive men who may not have resources.
What did Baker et al find?
Baker et al found results from one magazine survey of over 2700 UK women, 14% of the population could be due to extra-marital affairs supporting this theory of sex differences and parental investment.
Criticisms of Baker et al’s study?
The issue here however is that the sample is very small in comparison to the population of the UK which is over 60 million and it is difficult to extrapolate such data to wider generalization. Also the sample suffered from cultural bias with it focused only on UK women meaning results may be ethnocentric and not across other populations. Also the results being from particular types of magazines may in fact attract a certain demographic of readership - the content about extramarital affairs may actually attract those that engage in such behaviour further biasing the results. Therefore it is hard to establish cause and effect from such survey results.
Explain Buss et al’s study.
Buss et al found that male US students indicated more concern about sexual infidelity where as female students expressed a greater concern over emotional infidelity. This was also supported by physiological responses when respondents were asked to imagine scenes of sexual or emotional infidelity. Men showed more distress with sexual rather than emotional infidelity.
Criticisms of Buss’ study?
This supports the theory however the results here were only from US students suggesting cultural bias and making cross-cultural application difficult. The age group may also not be indicative of the whole population as they were simply young adults and the results given may simply be more indicative of that age group rather than the wider population.
Why would joint parental care be more desirable in humans?
Because of the high costs of successful reproduction. In any situation where males can increase the success of childrearing it would be in their benefit to do so and this is for the most part what appears to happen in most human populations.
What did Andersson find?
Andersson et al looked at investments by fathers in the college education of biological and step-children finding they were highest when the biological father lived with the mother of his children. This would initially support such an evolutionary theory however in all other instances investments were equal which does not appear to support the theory overall.
Further criticisms of the theory?
- Such a theory in explaining sex differences is reductionist as it attempts to explain human behaviour down to simple evolutionary explanations with us governed by “nature” rather than “nurture” negating social and cultural influences completely. In truth human behaviour is far more complex with all elements likely playing a role in some form rather than one (nature).
- The theory is also deterministic as it does not factor in peoples ability for conscious thought and free-will. Many females care for children that are not her own in relationships as do men. Couples even adopt putting in equal amounts of energy despite there being no biological link either highlighting this ability to break away from our genetic programming.
- As with most evolutionary theories, attempting to explain differences in investment between the sexes is heavily based on post-hoc evidence that is difficult to conclusively prove or disprove. Popper argued theories that cannot be scientifically proven remain speculative and this is one big criticism of such an evolutionary explanation for differences.
