Studies

female monkeys who were deliberately exposed to testosterone during prenatal development later engaged in more rough and tumble play and were more aggressive than other female monkeys

However the study focused on animals, and thus cannot be generalised to people as prenatal development may differ from moneys to humans

When Bruce was circumcised as a baby, his penis got burnt off. John Money recommended to raise him as a girl called Brenda as he believed gender was not set until one was two years old (due to nurture). Growing up, despite female hormonal treatments, Brenda reported feeling uncomfortable with who she was and was seen to be wanting to play with her twin brothers toys and showed particularly masculine behaviour. Due to failing to identify as female, he was eventually told the truth, in which he reverted to his true sex, becoming David, showing how nature overrides nurture

However this is a case study - one person cannot be generalised to the entire wider population

16 genetically born males born with virtually no penis. 14 were raised as girls, but two were raised as boys. By aged 16, eight had reassigned themselves as male. Showing how bio factors play a role in gender development

But it cannot be ignored that six of them stayed as girls, showing how nurture affected them

Used personal ads to assess what men and women were seeking and also what they were advertising. They found that 44% of men looked for a physically attractive partner compared with 22% of women, 50% of women offered attractiveness whereas only 34% of men did

in women oxytocin levels increased with stress, a hormone which reduces anxiety and makes people more sociable (tend and befriend)

This is scientific research, increasing its validity

Developed a questionnaire with questions like “when I watch a film I prefer to be with a group of friends rather than alone”. Ppts were asked to indicate how strongly they agreed or disagreed with the statements. Males tended to be systematisers and females tended to be emphasizers – only about 17% of men had a female emphasizing brain and the same percentage of women had a male systematizing brain

However, this is a self report method and thus ppts may be affected by demand characteristics and/or social desirability 

Explored what males and females looked for in a marriage partner and studied over 10,000 people from 37 different cultures, including a wide diversity of ethnic, religious, political and economic groups. It was found that women desired mates who had good financial prospects; men placed more importance on physical attractiveness and wanted mates who were younger than them. This suggests that particular gender roles have been universally evolved to guarantee success when it comes to survival and reproduction. A strength of the sample is that is has high population validity because 10,000 people from 37 different cultures were studied. This wide diversity means that it is not bias and thus able to generalize findings to the wider population. However, Eagly and Wood still suggest the findings can be interpreted to support the impact of social roles as the countries with greater gender equality scored lower on differences in gender roles therefore suggesting it is not down to biology/evolution but more so social conditions 

A biological male had sex reassignment to become female due to damage to his penis. Despite some male behaviour, they perceived themself as female, showing how nurture can override nature as Money suggests

However, case study - not representative 

When Bruce was circumcised as a baby, his penis got burnt off. John Money recommended to raise him as a girl called Brenda as he believed gender was not set until one was two years old (due to nurture). Growing up, despite female hormonal treatments, Brenda reported feeling uncomfortable with who she was and was seen to be wanting to play with her twin brothers toys and showed particularly masculine behaviour. Due to failing to identify as female, he was eventually told the truth, in which he reverted to his true sex, becoming David, showing how nature overrides nurture

However, case study - not representative 

16 genetically born males born with virtually no penis. 14 were raised as girls, but two were raised as boys. By aged 16, eight had reassigned themselves as male. Showing how bio factors play a role in gender development

But it cannot be ignored that six of them stayed as girls, showing how nurture affected them and therefore (to an extent) supports Money's proposal of how nurture overrides nature

The number of neurons in the BSTc of MtF transgenders was similar to that of females. By contrast, the number of neurons in an FtM transgender was found to be in the male range. This tells us that the BTSc can be said to be a cause of gender dysphoria

Scientific/empircal evidence = high in validity 

found similar results to Zhoul (BUUUUT Hulshoff Pol and it was found that in both these studies the individuals had been receiving hormone therapy and so it could be said that the outcomes was due to the therapy and its influence on the size of BTSc)

empircal evidence = high validity 

Brains of FtM transgenders were studied before they started transfer hormone therapy. The FtM individuals had a more similar pattern to individuals who share their gender than those who share their bio sex suggesting the number of neurons in the BTSc has an effect on gender

validity high bc of empirical evidence

Noted that most transgenders reported feelings of gender dysphoria from an early age in their childhood, but it was found that the differences in volume of BTSc actually developed in adulthood and suggests rather than a cause, it’s an effect of gender dysphoria

115 boys and their mothers were studied. 64% of the boys who were identified with gender dysphoria were also diagnosed with separation anxiety disorder, thus pointing to a disorder attachment with their mother – but suffers from gender bias

studied 435 individuals experiencing gender dysphoria found that these did not report a greater number of mental health issues than those who were not experiencing gender dysphoria. Suggests gender dysphoria is unrelated to childhood trauma

concludes that gender dysphoria remains a mystery despite intensive research, and that it’s likely to be due to an interaction of psychological and biological factors

Studied 70 gender dysphoric boys finding there was no evidence to suggest a biological cause. One common factor between them all however is that they lacked a male role model. This adds strength to psychological explanations because it attempts to explain gender dysphoria through modelled behaviour and learning

found two year olds were 76% correct in identifying their sex whereas 3 year olds were 90% correct (supporting gender labelling)

asked young children ‘were you a little girl or a little boy when you were a baby?’ and ‘when you grow up will you be a mummy or a daddy?’ children did not recognise that these traits were stable over time until they were three or four year olds (supporting gender stability)

children of several cultures seemed to follow through the 3 stages  population validity as the theory can be applied to different cultures – supports the idea of it being universal

They found children aged under 4 showed no signs of gender constancy or stability however did show strong signs of stereotypes in regards to gender roles. This highlights gender specific behaviour has been acquired before Kohlberg’s theory which is in line with the gender schema theory

Children were asked to recall pictures of people, children under six recalled more of the gender-consistent ones (such as a male fire fighter or female dancer) than gender inconsistent ones (such as a male nurse or female chemist) – these findings are in line with the theory as children appear to absorb in-group info more than out group info

Told 4-9 year olds that certain gender neutral items (e.g. pizza cutter) were either boy or girl items. Participants took a greater interest in toys labelled as in-group. Also, one week later, they were able to remember more details about in-group objects. This shows how gender schema are related in particular to memory (organisation of info)

Found that 3-4 year olds tend to act in gender typical ways before developing gender specific schemas for their in group. The children justified their choice of gender stereotypic toys without referring to gender stereotypes – gender development is innate, refuting theory

Observed mothers playing with an infant who was either presented as a boy (in terms of clothing), or as a girl. The mothers selected gender appropriate toys (e.g. a doll for girls) and also responded more actively when a “boy” showed increased motor activity, showing the role of differential reinforcement from parents for gender development

found that parents who show the clearest patterns of differential reinforcement have children who are quickest to develop strong gender preferences

Showed clips to children 8-9. In the film boys and girls were seen as either selecting an apple or a pear (both gender neutral items). Later the children were given the choice of fruit. Boys selected the fruit they had seen another boy selecting and the same happened with girls 

bobo doll experiment where children watched a film of adults interacting with a bobo doll. Children who had been in the aggressive condition reproduced physical and verbal behaviour, whereas children in the non-aggressive condition exhibited virtually no aggression, highlighting the importance of modelling, imitation and media. Children also identified/imitated best with adult of same sex, showing how they are more likely to adopt gender roles this way. Further research showed the significance of reinforcement – children who saw the adult model rewarded for aggressive acts showed a high level of aggression, compared to those who saw the model punished or receiving no reward

Found that children in a Canadian town with access to multiple TV channels had more strongly sex typed views than children in towns with one or no TV channels. This suggests that exposure to gender stereotypes from TV increases sex typed views

Some psychologists (such as Maccoby) hold the view that peers are the most important social agents of gender development, and there is a large amount of research evidence that demonstrates the importance of peers. However, Lamb & Roopnarine found that pre-school children simply reinforce gender role stereotypes rather than creating new ones. This suggests that peers are less important to gender development in early childhoods.

Despite the evidence showing the influence of parents, they found no significant differences in the extent to which boys and girls are reinforced for aggressiveness or autonomy, two things which vary between the genders. Studies have also found few gender differences in terms of parental warmth, discipline, or encouragement of achievement or dependency. This findings refute the influence of parents in establishing gender roles.

Explored gender stereotypes in 30 different nations involving 2800 university students as participants. They were given a 300 item adjective checklist and asked to decide whether it was most associated with men and women. They found that there was a broad consensus across countries with men being seen as more dominant and aggressive and women being seen as nurturing and deferent. This suggests that gender roles are universal and so these similarities imply nature is the overriding factor when determining our gender. A strength of the sample is that it is a cross cultural study and thus has population validity as it does not apply one cultures findings to all, however the list itself suffers from imposed etic as they assume that the adjectives may be viewed differently in different cultures. Also, they only studied university students and so they may have different experiences regarding gender e.g. they’re more open to change to different generations (flexible/fluid/liberal/progressive) as thus cannot generalize to all. The construction of the checklist does not include an equal category alongside the male and female categories. This reduces the validity of the data because the participants are forced to put it into either group and thus cannot say both and so findings of a difference in gender roles may be exaggerated SIMILARITIES

Buss explored what males and females looked for in a marriage partner and studied over 10,000 people from 37 different cultures, including a wide diversity of ethnic, religious, political and economic groups. It was found that women desired mates who had good financial prospects; men placed more importance on physical attractiveness and wanted mates who were younger than them. This suggests that particular gender roles have been universally evolved to guarantee success when it comes to survival and reproduction. A strength of the sample is that is has high population validity because 10,000 people from 37 different cultures were studied. This wide diversity means that it is not bias and thus able to generalize findings to the wider population. However, Eagly and Wood still suggest the findings can be interpreted to support the impact of social roles as the countries with greater gender equality scored lower on differences in gender roles therefore suggesting it is not down to biology/evolution but more so social conditions SIMILARITIES 

Looked at male superiority on spatial perceptual task and gender differences in conformity in 17 societies. Male spatial superiority and higher levels of conformity in women was only found in relatively tight knit, sedentary societies; no difference in spatial abilities and conformity levels was found in nomadic societies. Van Leeuwen argues that this can be explained by looking at the way labour is divided. In nomadic societies both men and women would need to hunt and therefore be worth the same, women would not be expected to conform. Similarly, both men and women would develop good spatial skills as children so that they can hunt.  This suggests the difference and change in societies shows it is down to social influences rather than biological factors as biology has not changed but social situations have and thus society is changing and therefore this is what it has to be affected by. This can be used to explain feminism as men and women are actually equal in terms of bio factors e.g. spatial skills as it has been learnt therefore women are becoming more equal. Supports this theory because greater gender equality equals fewer rigid gender roles. Typically biology based skills can be learnt/developed depending on societies DIFFERENCES