Right-left asymmetry in position learning of male chicks.

Two-week-old chicks were trained to discriminate between two identical boxes on the basis of their position. The positive box was placed against the wall facing the entrance of the test cage, whereas the negative box was placed either on the right or on the left wall. Results showed that male chicks learned the task faster when the negative box was placed on the right than when it was placed on the left, whereas no right-left asymmetry appeared in females.