Applying a quantitative genetics framework to behavioural syndrome research

Current interest in behavioural syndromes, or 'animal personalities', reinforces a need for behavioural ecologists to adopt a multivariate view of phenotypes. Fortunately, many of the methodological and theoretical issues currently being dealt with by behavioural ecologists within the context of behavioural syndromes have previously been investigated by researchers in other areas of evolutionary ecology. As a result of these previous efforts, behavioural syndrome researchers have considerable theory and a wide range of tools already available to them. Here, we discuss aspects of quantitative genetics useful for understanding the multivariate phenotype as well as the relevance of quantitative genetics to behavioural syndrome research. These methods not only allow the proper characterization of the multivariate behavioural phenotype and genotype-including behaviours within, among and independent of behavioural syndrome structures-but also allow predictions as to how populations may respond to selection on behaviours within syndromes. An application of a quantitative genetics framework to behavioural syndrome research also clarifies and refines the questions that should be asked.