An example of an alpha-biased theory is Freud's psychosexual theory. Freud represented women as being less morally mature than men, in that their super-egos were less well developed (because they had not experienced castration anxiety). By representing women in this way, Freud was legitimising the treatment of women as second-class citizens in Victorian society. It is not surprising, therefore, that women were excluded from many professions in Freud's time, and were even denied the vote. Feminist critics of Freud's theory claim that Freud was simply reflecting the sexism of his time, and was therefore building cultural sexism into his theory rather than offering an objective, scientific view of male and female development.
Another alpha-biased theory is Kohlberg's theory of moral development. Kohlberg believed that the average male would reach at least stage 4, whereas female would reach only stage 3. The difference between these stages is that one reflects social morality (e.g laws) whereas the other reflects morality of personal relationships. Kohlberg thought that the latter was less mature. This view was criticised by Gilligan who claimed that women were not morally inferior to men but spoke in a different moral voice, based on care and responsibility rather than being dominated by male notions of justice. She suggested that Kohlberg had obtained his results because of the very abstract dilemmas used in his research, but when using real life dilemmas (e.g whether to have an abortion), women showed just as much evidence of mature moral development.
Critics of Gilligans theory (e.g Unger and Crawford) have argued that Gilligan's research was not comparable with the rather more abstract dilemmas faced by Kohlberg's subjects. Gilligan was also accused of showing a failure to explore factors other than gender which could be related to differences in moral reasoning (e.g social class, education, race/ethnicity). Finally, Gilligan failed to explore the possibility that what appeared to be a sex difference in moral reasoning, might also reflect women's subordinate social position, with perhaps the ethic of "care and responsibility" being expressed by less powerful people generally, rather than just women.
Many other theories in psychology have typically ignored possible differences between men and women. For example, the lifespan theories of Levinson and Erikson tended to focus on male development with the apparent assumption that female development will follow the same pattern. This concentration on male development in these theories is an example of the androcentric bias in psychology, in that ideas of "normal" behaviour are drawn almost exclusively from studies of the development of males. The danger of this approach is that we make assumptions about what is "normal" development based on a biased sample. Any deviation from this is then seen as evidence of abnormal development, and legitimises prejudice against the "deviant" group (in this case, females).
Questions about similarities and differences between the sexes are not just scientific questions, they may also be seen as highly political. Research has attempted to answer important questions about the differences between males and females using traditional experimental designs that lack the sensitivity to explore the questions being asked. The results of such research have then been used to exclude women from some occupations or to represent women as being victims of their own bodies. Menstruation has, in particular, captured the imagination of both scientists and feminists. The 'discovery' of prementrual syndrome, during which female hormones become so unstable as to aparently render some women capable of murder, has led to a great deal of experimental research in this area (e.g Nicolson, 1997). Nicolson argues that many of the performance and mood differences traditionally identified between premenstrual women and others were products of poor research design. Several other well-designed studies, she claims, reported no differences but these were not published, as their findings were subject to doubt.