Psychological adaptation
[4] On the other hand, Steven Pinker presents the cognitivist perspective in his book, The Blank Slate, in which he challenges the tabula rasa models and argues that human behaviour is shaped by psychological adaptations.
[6] However, sexual preferences are a difficult subject to test due to the amount of variance and flexibility exhibited in human mate choice.
Evolutionary psychologists argue that incest avoidance adapted due to the greater chance of producing children with severe disabilities when mating with relatives, and because genetic variability offers an increase in fitness regarding offspring survival.
[9] For example, the tendency for females to change their sexual strategies when faced with developmental pressures such as an absent father may be the result of a psychological adaptation.
Evolutionarily, it pays for a male to be polygynous – to have a number of female partners at once – because it means he can create more offspring at once, as they don't have to invest any time in carrying a foetus.
Evolutionarily, it is thought that males have a desire to reproduce as much as they can, and short-term relationships are a good way to inseminate many women with his sperm in order for his genes to continue through generations.
[17] Female sex-specific adaptations provide evidence of special design for the purpose of increasing fitness and in turn, reproductive success.
[18] For example, mate choice, rape aversion tactics and pregnancy sickness are all female-specific psychological adaptations, identified through empirical research, found to increase genetic contributions through survival and reproduction.
David Buss, an evolutionary psychologist, examines the fundamental principles of selection pressures that create human mate preferences in his contribution to the publication The Adapted Mind.
[24] Females show a psychological adaptation to detect mate quality using these hormonal cues which display the male's fitness and reproductive value.
[26] This is because rape poses severe costs for the female such as pregnancy, physical harm, injury or death, relationship abandonment and self-esteem depletion.
[27] The greatest cost to the female is the circumvention of her mate choice, which threatens reproductive success, resulting in the possession of adaptations in response.
[31] Evidence for this as an adaptation can be seen in reproductive-aged women who are found to experience more psychological pain following rape due to an increased risk of conception.
[32] Research also suggests that women in the fertile phase of their menstrual cycle perform fewer risky behaviours that could potentially result in the risk of rape.
[33] Women's capacity to resist rape also changes relative to their menstrual cycle; females in the fertile phase show an increase in handgrip strength when placed in a threatening, sexually coercive scenario.
[37] Particular plant foods, whilst unharmful to adults, can contain toxins (e.g. teratogens) that are dangerous for developing embryos and can potentially cause birth defects such as facial asymmetry.
Evidence lies in the finding that women who experience more extreme cases of pregnancy sickness tend to be less likely to miscarry or have babies with birth defects.
Pregnancy induced sickness only typically occurs 3 weeks after conception, around the time when the embryo has started forming major organs and is therefore at the highest risk.
