Gender refers to the attitudes, feelings, and behaviours that a given culture associates with a person’s biological sex. Many biological psychologists believe that gender development is directly caused by the influences of genes and hormones alone.
Each person has 23 pairs of chromosomes. Each chromosome contains hundreds of genes which contain instructions about the physical and behavioural characteristics (e.g. eye colour). Females XX, males XY, sex determined by father’s sperm. Half of sperm contains an X chromosome, half Y chromosome. As all female’s eggs contain X chromosomes, everything develops as a female unless instructed otherwise. Sex is determined by which sperm fertilises the ovum. If the Y chromosome succeeds, this leads to the development of glands which produce male androgens (sex hormones i.e testosterone).This then leads to the formation of male external genitalia and changes in brain development, thus directly affecting gender development.
Sometimes there are problems such as when a boy (XY) foetus is insensitive to androgens, also known as androgen insensitivity syndrome. As a result, the person has some or all of the physical traits of a woman, but the genetic makeup of a man.
There is evidence to support the biological view by Quadagno (1977this study focused on female monkeys and exposing them to prenatal testosterone, it was found that they engaged in more rough and tumble play than other females, and were more aggressive. Thus showing the huge importance hormones and likely genes have on gender development. However, this research can be criticised as it was carried out on monkeys rather than humans, although it has been claimed that monkeys are very genetically similar to humans, the results should not be generalised to humans as it could be that monkeys are more sensitive to hormones such as testosterone than humans meaning the results are not valid for humans. Furthermore Quadagno’s study was a Laboratory experiment meaning all variables were tightly controlled which is unlikely to happen if the experiment was carried out on human participants.
The biological approach to gender development stresses the idea of nature rather than nature. However, there is criticizing evidence by John Money said that it wasn’t biology that influenced gender development; however it was nurture as well. This was supported by Reiner and Gearhart that studies 16 genetic males, raised as females. By the age of 16, 8 had reassigned themselves as males, and the other 6 remained females. This supports that it is both nurture and nature that influences gender development. However, these studies can cause ethical issues as researchers are using inter-sex individuals which can be more vulnerable than “normal” individuals. It is also a reductionist approach as it reduces our behaviours and gender down to biology, however doesn’t take into account the behavioural approach which suggests we learn behaviours, and gender through indirect learning.
Money (1972) used a case study to support the idea that hormones affected gender development. Money studied a group of girls that had been exposed to high levels of testosterone ‘in utero’ through anti miscarriage drugs. These girls were compared to their non-exposed sisters and their mothers were asked to comment on their behaviour and choice of toys/clothes. A difference was reported, with the exposed girls being reported as more boyish with a higher IQ.
This suggests that exposure to high levels of androgens had affected their gender development. Nevertheless, it has been suggested that the questions were misleading such as ‘Which of your daughters are more boyish’ suggesting that one of them has to be boyish. A follow up study found only one difference – the exposed girls were more active. Hines also disagreed with Moneys findings and so carried out a study examining play shown by girls and boys aged 3-8 years who had congenital adrenal hyperplasia (CAH – When embryos are exposed to high levels of androgens). Hines found minor differences, except girls preferred playing with boys, which suggests that hormones had little effect on behaviour.