A graphic representation of the effects of cohabitation upon aggression in pregnant mice

Cohabitation with a pregnant cagemate tends to stimulate aggression of a pregnant mouse as well as a nonpregnant (but mated) female resident mouse toward male intruders [Buhot‐Averseng and Goyens, 1981]. An illustration of these results provided by three measures of aggressiveness is proposed, using a new type of simple geometric graph. These graphs allow an easy comparison between the measures used and between the different experimental groups with regard to both of the following factors: (1) mating and pregnancy in the subject, and (2) presence and pregnancy of a cagemate.