A study, which supports the role of hormones and thus the biological explanation of gender, is Young (1966). He changed the sexual behaviour of both male and female rats by manipulating the amount of female and male hormones that rats received during their early development. They displayed “reversed” sexual behaviour. Young believed that the exposure had changed the sexually dimorphic nucleus. This shows support for the biological explanation of Gender because the alteration of hormones can affect gender characteristics. For example, when females were given male hormones, they displayed male gender behaviours, rather than feminine, which you would expect in the female rats, even if hormone levels were changed, therefore supporting the biological approach.
A methodological evaluation point of Young’s study is that it was conducted on animals. This means that the results cannot be generalised to the human population as the role of hormones on gender in rats may be very different than the response of the human body to certain amounts of hormones, thus lowering the validity of the study in supporting the biological explanation of gender.
Evidence against the role of hormones on gender includes Hines study. Hines (1994) examined the amount of “rough and tumble” play in girls and boys aged 3-8 years, who had CAH. Comparisons were made to a control group. The only differences between girls with and without CAH were that those with CAH preferred playing with boys. This suggests that exposure to high levels of male hormones lead to only minor effects on behaviour. This contradicts the biological explanation of gender as it shows that elevated testosterone levels in the womb do not necessarily cause masculine behaviours after birth. This is shown in the level of differences between the girls with CAH and without CAH, therefore contradicting the biological explanation of gender.
Durkin (1995) proposed evidence against the biological explanation of Gender. He said that if sex differences are due to biological differences we would expect to see these differences before social experiences start to have an effect. There is no evidence of early differences between baby boys and girls in terms of temperament or behaviour. This contradicts the biological explanation of gender because any gender differences between boys and girls could be due to parenting or social experience instead of biological factors because the vast majority of research is on children over 12 months.
A study that supports the role of genes as part of the biological explanation of Gender is Imperato-McGinley et al. study on a remarkable family who lived in the Dominican Republic. Of the 10 children in the Batista family, four of the sons have changed from being born and raised as girls into muscular men: they were born with normal female genitalia and body shape, but when they were 12, their vaginas healed over, two testicles descended and they grew a full size penis. Many other families also experienced this phenomenon and they were found to have a common ancestor who passed on a mutant gene. This shows support for the biological explanation of gender as it shows that the mutant gene changed the children’s sex from female to male during the hormonal stage in puberty, and despite being raised as girls their gender also changed from feminine to masculine, and they also mentally overcame the social experience of being raised as girls, suggesting a change in genetic structure. This shows the influence of genes on gender and thus supporting the biological approach.
A methodological evaluation of this study is that it is a case study on just one community in the Dominican Republic. The case study only applies to the Batista family and the results cannot be extrapolated, as it was only due to a mutant gene in a common ancestor, therefore lowing its validity in explaining gender as a biological phenomenon.
The nature/nurture debate is an intrinsic aspect of Psychological theory. Nature refers to Gender being determined by innate factors, while nurture deems culture and social environment as responsible. The biological perspective suggests that a person’s gender is innate and the same as their biological sex, as it is determined by genetic makeup and hormonal influence at conception. Therefore, the biological approach only supports the nature side of the debate, which does not address the importance of nurture and sociocultural environment on human gender identity. This limits the theories influence – as it is important to recognise that most human behaviour is due to a combination of both nature and nurture.
The biological explanation of Gender can be seen as Deterministic. Determinism states that an aspect of human behaviour is ingrained in us and that we are pre-programmed robots allowing no room for an individual’s free will. The biological perspective suggests that a person’s gender is innate and the same as their biological sex, as it is determined by genetic makeup and hormonal influence at conception. Therefore, the biological approach only supports the deterministic approach, which does not allow any movement for the effect of free will on human gender identity and doesn’t apply for gender disruption.