Reproductive behavior of the guinea pig. II. The ontogenesis of the reproductive behavior pattern.

Abstract

Thirteen of the [male] responses are exhibited before 60 days of age, each response appearing at a rather definite and predictable age. Further evidence for the division into courtship and copulatory responses is furnished by the relatively long period elapsing between the day of appearance of the last new courtship response and the first copulatory act. The very young [female] is aggressive, her behavior resembling that of a receptive adult in this respect. However, when the [male] becomes active aggressively, at about 40-50 days of age, the behavior of the [female] becomes that of a non-receptive adult. Differences in the age at which the various responses first appear were found between LM and NLM pairs; the LM being, on the whole, slower in the development of the pattern. That some stimulus peculiar to animals of the same litter presented an in-hibiting influence on the LM males'' behavior was suggested in explanation of these differences. The data for 3 experiments, viz., [male][male] and [female][female] (1) separated until 30 days of age, and then put together for 5 min. each day, (2) put together 5 min. each day from the age of 10 days, and (3) put together 25 min. each day from the age of 10 days, seem to indicate that physical maturation is of more importance in the development of the reproductive behavior pattern in the guinea pig than experience gained from association with animals of the opposite sex.