A genetic analysis of aggressive behavior in two strains of mice

Examination of BALB/cJ and A/J mouse strains revealed marked differences in their levels of isolation-induced aggression. Using the dangler paradigm, we found that BALB/cJ males were uniformly aggressive, while A/J males showed no tendency to attack. Genetic analysis showed that the expression of aggressive behavior in the F1, F2, and backcross generations was consistent with the transmission of high aggressivity as a single, autosomal recessive trait. Although the data are consistent with a major-locus effect, more complex polygenic modes of inheritance have not been excluded.