Systems genetics of behavior: a prelude

- Systems genetics is a new approach to study behavior.
- Systems genetics integrates variation among individuals at multiple levels.
- Multiscalar models are used to predict behavioral variation.
- Systems genetics should provide a more holistic approach to understand behavior.

Behaviors are among the most complex phenotypes - the end product of intertwined networks of genetic, molecular, cellular, physiological, environmental, and social factors. While reductionist methods that test contributions of single genes are crucial to define components of behavior, there are now complementary integrative methods that can model and predict behavior in a more global context. Systems genetics is a new field that exploits massive multiscalar data to study patterns of covariation in complex biological systems. As applied to behavioral genetics, this field looks inside the black box to understand hierarchies of molecular and cellular traits and connections that link gene variants and environment to behavior. Here we explore recent progress and challenges in this new field.