Gender bias can ultimately negate the validity of many theories and studies as it can lessen its universal applicability to humanity. Gender bias is found in psychological theories, research, and even the way research is undertaken. When discussing examples of gender bias, it is important to first outline the different forms gender bias can have. Alpha bias acknowledges valid and lasting differences between the two genders and can have the effect of reinforcing gender stereotypes, whereas beta bias minimises or even ignores the differences between women and men. Both types of bias are thought to have evolved from androcentrism - that is Psychology being dominated by males and/or masculine interests where male behaviour is perceived as ‘the norm’. One example of gender bias in psychological theories in the psychodynamic work of Freud; Freud attempted to explain femininity as a variant of failed masculinity, his work illustrates women as inferior to men, largely due to supposed ‘penis envy’. The alpha bias in Freud’s work extended to explaining the vanity of women, by stating that women wish to make up for their initial sexual inferiority by focussing on their physical ‘charms’. Freud also noted that females were unable to experience the same Oedipus complex that was crucial to a boy’s gender development. However, despite Freud’s research being obviously gender biased, some psychologists, notably Bruehl, have dismissed this as merely being the result of the patriarchal society in which he lived. Other critics, including Honey (1926) state that Freud overlooked the fact that men may envy a woman’s ability to conceive and bear offspring, he assumed that women had ‘nothing worth envying’. Another psychologist’s work that has come under fire is Kohlberg. Kohlberg’s dilemmas were based on abstract, male-orientated principles, by which he produced a theory of moral reasoning which he claimed represented both males