Social "Learning" in Domestic Chicks )

Sociai facilitation is considered to occur when there is an increment in the performance of an activity, this increment being the result of the presence of another individual or individual surrogate, i.e. some substitute for the second organism such as characteristic vocalization or movement. In developing the experimental design, it was assumed that social facilitation would occur in varying amounts depending on the degree to which the test situation was made social. It was assumed further that mimicry or imitation, if it occurred at all, would occur as an increment in performance greater than that to be attributed to social facilitation alone. For these reasons then, several groups were used in order that a "gradient" of social facilitation might be demonstrated. One group ran a straightaway with no other chick present, a second group ran the straightaway with a second chick serving as a lure in a cage located behind the goal cage, and a third group ran the straightaway in pairs, neither members of the pair ever having had previous experience in the problem. These three groups were assumed to be experiencing an increasingly social learning situation. If mutual mimicry occurs in running a straightaway, it would result in each subject's increasing its running speed on paired, over its running speed on individual trials. To test this, another group of subjects was formed, each member of the group running half the trials alone and half the trials as a member of a pair. To determine whether mimicry would occur in the task presented to the chicks it was necessary to supply another component to the problem, namely that of pre-training one member of each pair of chicks. By comparing pairs of chicks having no previous experience in a straightaway with untrained chicks which ran the straightaway in the company of a trained partner, any superiority of the latter group could be attributed to the presence of the trained chick. In addition to the factor of pre-training, the factors of breed discrimination and flock residence or non-residence were investigated. On the basis of the results obtained from the present investigation the following conclusions seem to be waranted : (1) Chicks which were run to a goal involving another chick of the same breed learned to run a straightaway more rapidly than chicks which were run only to a non-social goal. (2) Pairs of chicks which had no previous experience in a straightaway learned to run it more rapidly than either chicks run to a non-social goal or chicks run to a goal consisting in part of another chick serving as a lure. (3) When a group of chicks were run on the straightaway two trials as individuals and two trials as pairs, the speed scores on the paired trials were significantly higher than the speed scores on the individual trials. (4) Chicks which were run on a schedule which included two trials in isolation and two trials in pairs, were slower on the isolation trials than chicks run in isolation regularly. They were also slower on the paired trials than pairs of equivalent background which were run regularly as pairs. (5) When untrained chicks were paired with a trained chick of the same breed and from the same flock, the highest speed scores were obtained indicating that the trained chick had a significant effect on the untrained chick. (6) Any trained chick, even one of a different breed or from a different flock than the untrained chicks, was more effective in increasing the speed at which the straightaway was travelled during the first session, than was another untrained chick of the same breed and from the same flock as the partner.