The persistence of social attraction in socially deprived and satiated rats

Pairs of socially deprived or satiated rats were observed for 71÷2 continuous hours in an open field. Social contact increased monotonically throughout this time, with socially deprived animals showing more attraction, and a greater increase in attraction, than satiated animals. The quality of social contact changed, however, from a predominantly active interaction, in which the most sociable animals were most mobile, to a predominantly passive huddling, in which the most sociable animals were least mobile. The results suggest that social attraction in rats is not transitory, and may serve several different functions.