Behavioural development in the Mongolian gerbil ( Meriones unguiculatus)

Appearance of behaviour patterns, their relative frequency of performance, pup-pup and pup-mother interactions were studied in gerbils raised under two levels of stimulation. Pups spent most of their time sleeping or nursing until day 18 (just prior to eye-opening) when many new patterns emerged and activity increased greatly. The more-stimulated groups spent significantly more time quietly than the less-stimulated group and a treatment×days interaction was found for sitting alert. No differences between both groups of mothers were found but both retrieved very infrequently as compared with rats and mice. The significance of these findings was discussed in light of hypotheses relating amount of infantile stimulation to later emotionality.