Introduction

The reader who has followed our current account of Sex and Gender and is also familiar with our previous edition is probably struck by a number of changes that have occurred in the past 15 years. In particular, the piecemeal and generally atheoretical approaches of earlier research have given way to coherent statistical investigations and ambitious conceptual models. In this final chapter, we comment upon these changes and suggest the direction studies of sex differences may take in the future.

In the first section, we explore the limitations of meta-analysis, the technique that we described in chapter 1, and which is currently used to summarise systematically a body of research evidence. Throughout the following chapters, we drew upon meta-analyses to provide summaries of sex differences in behaviour such as sexuality, mental health, parenting, and cognitive capacities. Here we consider the problems that may be encountered by even the most thorough meta-analysts. Our focus is on the databases that have been used for the meta-analyses, rather than the statistical techniques. In particular, the databases are restricted in terms of age-range, cultural identity, and historical time.

In the second part of the chapter, we consider two theoretical developments that have changed the way we view sex and gender and how it is studied. These are evolutionary psychology and social role theory. Both represent broad pictures of the origins and immediate causes of sex differences in social behaviour and cognition.