Associative learning in pairs tends to reduce individual differences in performance: An experiment with zebra finches (Taeniopygia guttata).

The maintenance of individual differences in cognitive performance is puzzling given that cognitive performance is frequently correlated with fitness components. Cognitive performances are typically measured under laboratory conditions, in which individuals cannot observe others. Under natural conditions, however, observational learning would allow individuals with poorer cognitive abilities to improve their performance by copying the choices of more skilled individuals.