An aspect which must be considered when judging if Psychology as a discipline is sexist (particularly when looking at older example studies such as Freud) is...
Stricklund (1987) - 1/3 of all Psychologists and more than 50% of those with a PhD in Psychology were female in 1987 - likely similar if not higher figures today.
Evidence that Psychology is less sexist than it once was comes from...
Kitzinger & Coyle (1995) - heterosexism in Psychology has moved through 3 phases - currently in liberal humanism plus where similarities between homo/ hetero relationships are accepted but key differences are also researched/ considered.
Evidence that heterosexism in Psychology is declining comes from...
An approach to cross cultural research where cultural differences in behaviour are studied from outside the culture - many cross cultural studies in Psychology adopt this approach.
When a behaviour which is culturally specific (emic) is mis-interpreted as culturally non-specific (etic). When this happens the behaviour is often categorised or judged using Western ideas of "normality".