Gender Development -Studies

Evidence FOR the biological explanation:
BRUCE/BRENDA- Dr Money (a behavioural psychologist) studied David Reimer who was an identical twin... as an infant David's penis was damaged during curcumcision. As a behavioural psychologist dr money beleived that babies are born as 'blank slates' and so learn everything (through conditioning), he therefore believed that david could be brought up as a girl (called Brenda). Dr money saw this as a success story.. Everything was fine until puberty: testosterone caused changes in the body as the biological makeup (genotype) was male not female; Brenda said she never felt right as a girl, her parents eventually had to explain the circumstances. Reverted back to male and eventually got married and had kids.
+++Highlighted importance of nature over nurture in gender development 
------VERY unethical- he commited suicide. 

MORE EVIDENCE: Gorski conducted a study on rats.. he was able to produce male rodents that demonstrate feminine behavior by injectecting oestrogen and female rats with masculine behaviour by injecting testosterone. They also look and act more like males. 
--can we generalise from animals?

There are some more evaluations from both studies, you can think of a few? 

Damon (1977) Children of 4,6 & 9 years of age were told a story about 'George' who liked to play with dolls. They were asked whether it should be allowed: results.... the older the kids--- the more mature the answer answer, suggested children learn gender through 'meidating processes'. It is an active process. +++Supported Kohlberg's stage theory (gender constancy, identity and stability).
---potential researcher bias- (double blind exp. would eliminate subjectivity)

Martin and Halverson (1983) Showed schema consistent and inconsistent pictures (sex-stereotyped and not e.g. girl holding a gun) to 5 & 6 year olds. They children had to recall the pictures a week later and the results found that they often distorted the inconsistent pictures according to their 'schemas' (collection of knowledge about girls and boys) ++supports schema theory (attention-> schema emerges-> child adopts appropriate behaviour-> reinforces self image-> form a gender script-> focus on own sexes activities-> consistent behaviours assimilate).

These are only a couple of studies which you could use in an essay, you may have a few others, these are the ones that stick in my mind.

Fagot (1978) studied 24 families with children between the ages of 20-24 months. She OBSERVED (--researcher bias?) them 5 times in their natural environment (high ecological validity+) she recorded the behaviours they encouraged and discouraged. Results:
Encouraged:
Girls:Ask for help
Stay near parent
Play with dolls/dance
Show interest in clothes
Boys: Explore and be active
Develop muscle strength
Play with trucks and blocks 
Discouraged:
Girls: Running, Jumping and climbing
Boys: Asking for Help
Playing rough games
Playing with dolls
Doing feminine activities 

++supports the role that models play in influencing gender