Conceptual and methodological issues in the genetics of mouse agonistic behavior

Currently, 36 genes have been reported to affect offensive behavior in male mice. Potentially, these genes could be used to analyze the mechanism of this behavior. But there are methodological flies in this conceptual ointment. The studies with these genes varied in the genetic background, the maternal environments, the postweaning housing, the strain or type of opponent, and the type of test. The effects of each of these on the genetics of offense are reviewed with examples. It is concluded that between-study variation in these environmental or experiential circumstances may make it difficult to impossible to relate the effect of one genetic variant to another and to use these to identify and relate the pathways for gene effects on offensive behaviors. For this reason, standardization of these conditions is recommended.