There are no sex differences in cognitive ability but enduring sex differences in competitiveness, life goals, the relative emphasis on agency versus connection. Policy-makers' and feminist emphasis on equal opportunities and family-friendly policies assumes that sex discrimination is the primary source of sex differentials in labour market outcomes *notably the pay gap between men and women. However, some careers and occupations cannot be domesticated *examples are given *and this also poses limits to social engineering. Recent research shows that high levels of female employment and family-friendly policies reduce gender equality in the workforce and produce the glass ceiling. Preference theory is the only theory that can explain these new trends, the continuing pay gap and occupational segregation. Preference theory implies that there are at least three types of career rather than one. However, the differences between men and women's career goals are smaller than sometimes thought.Society is man-made [1], and human beings are malleable, in the sense of responding to incentives and sanctions, at least in the short run (Levitt & Dubner, 2005). It does not follow that social engineering [2] works on a completely blank slate (Pinker, 2002). Many differences between men and women that were believed to be fixed, and probably innate (Maccoby & Jacklin, 1974), have recently been shown to be socially constructed and artificial. Most notably, once women gained access to higher education after the equal opportunities revolution, sex differences in cognitive abilities evaporated. Today, females regularly outperform males in educational qualifications obtained at secondary school level, especially during compulsory schooling (EOC & OFSTED, 1996). Sex differences in verbal, mathematical and spatial abilities have now shrunk to small and insignificant levels (Hyde, 1996). However, some sex differences remain unchanged*notably in attitudes to sexuality, and what is often labelled as 'aggression' but extends to and includes rivalry and competitiveness as well as physical violence (Dabbs, 2000; Hyde, 1996 p. 114; Archer, 2004). A widely admired book by Gilligan (1982) argues that there are important sex differences in moral judgements affecting behaviour, which are sometimes summarised as differing emphases on agency versus connection. Reviews