All students and researchers of behaviour - from those observing freely-behaving animals in the field to those conducting more controlled laboratory studies - face the problem of deciding what exactly to measure. Without a scientific framework on which to base them, however, such decisions are often unsystematic and inconsistent. Providing a clear and defined starting point for any behavioural study, this is the first book to make available a set of principles for how to study the organisation of behaviour and, in turn, for how to use those insights to select what to measure. The authors provide enough theory to allow the reader to understand the derivation of the principles, and draw on numerous examples to demonstrate clearly how the principles can be applied. By providing a systematic framework for selecting what behaviour to measure, the book lays the foundations for a more scientific approach for the study of behaviour.

This volume is the first to aim at summarizing all of the scientific literature published so far regarding male-female differences and similarities, not only in behavior, but also in basic biology, physiology, health, perceptions, emotions, and attitudes. Results from over 18,000 studies have been condensed into more than 1,900 tables, with each table pertaining to a specific possible sex difference. Even research pertaining to how men and women are perceived (stereotyped) as being different is covered. Throughout this book's eleven years in preparation, no exclusions were made in terms of subject areas, cultures, time periods, or even species. The book is accompanied by downloadable resources containing all 18,000+ references cited in the book. Sex Differences is a monumental resource for any researcher, student, or professional who requires an assessment of the weight of evidence that currently exists regarding any sex difference of interest. It is also suitable as a text in graduate courses pertaining to gender or human sexuality.

All students and researchers of behaviour - from those observing freely-behaving animals in the field to those conducting more controlled laboratory studies - face the problem of deciding what exactly to measure. Without a scientific framework on which to base them, however, such decisions are often unsystematic and inconsistent. Providing a clear and defined starting point for any behavioural study, this is the first book to make available a set of principles for how to study the organisation of behaviour and, in turn, for how to use those insights to select what to measure. The authors provide enough theory to allow the reader to understand the derivation of the principles, and draw on numerous examples to demonstrate clearly how the principles can be applied. By providing a systematic framework for selecting what behaviour to measure, the book lays the foundations for a more scientific approach for the study of behaviour.

Sergio and Vivien Pellis have synthesized three decades of empirical research to create a remarkable work, unequalled in its field. A book that will not only expand our current knowledge of play behaviour, but will inspire change and progress from the laboratory to the playground.