Brings together many of the most active researchers currently using lizards to study the evolution of social behaviour, plus three well-known experts on behaviour of other taxa for an outside perspective. Each author begins by developing one or more hypotheses, then presents data on a specific lizard system that addresses these issues. The chapters are arranged in three sections that reflect the primary levels at which behavioural ecologists examine adaptive variation in social behaviour: individual variation within populations, variation among different populations of the same species, and variation among several species.