Ethanol effects on shock‐induced fighting and muricide by rats

Ethanol (0.25‐1 gm/kg body weight; IP) did not significantly alter shock‐induced fighting, regardless of whether it was administered to both rats or to only one rat of the pair. Higher doses tended to decrease shock‐induced fighting. Ethanol (0.25‐2 gm/kg body weight; IP) also did not induce “nonkiller” rats to kill mice and only high doses (1.5 and 2 gm/kg body weight) decreased the incidence of muricide in “killer” rats. The depressant effects of ethanol on both shock‐induced fighting and muricide appeared to result from drug‐induced ataxia rather than from a direct effect of ethanol on aggressive behavior.