Comparison of behavioural development in socially isolated and grouped rats

Isolated subjects engaged in more exploratory locomotion, oral consummatory behaviour, attentive immobility, pawing behaviour and tail manipulation and engaged in less sleep and rest than grouped subjects.

Abstract

The behavioural development of ten socially isolated and ten grouped rats was observed from 3 to 92 days of age under controlled laboratory conditions. Subjects were observed at the beginning of the dark part of the diurnal cycle. A time sample method was used to obtain data. Isolated subjects engaged in more exploratory locomotion, oral consummatory behaviour, attentive immobility, pawing behaviour and tail manipulation and engaged in less sleep and rest than grouped subjects. Some grouped subjects did not develop two non-social behaviours: pawing behaviour and tail manipulation. For most behaviours, differences between subjects were consistent over time. The percentage of time subjects engaged in each category of behaviour varied during development.