Three experiments investigated the discrimination of artificial patterns on
the basis of an underlying symmetry rule by pigeons. In Experiment 1, two
groups were trained to discriminate between different types of bilaterally
symmetric and asymmetric "chequerboard" patterns. In the second experiment,
we tested the ability of pigeons to generalize to novel patterns. Successf
ul transfer was confined to patterns similar to those used for training in
Experiment 1. Experiment 3 was designed to investigate the positive results
obtained by Delius and Nowak (1982). Naive pigeons were trained on tasks e
ither involving copies of their training patterns, or employing their train
ing procedure, or both. The behaviour of these pigeons was similar to that
found in Experiments 1 and 2 but different from that obtained by Delius and
Nowak (1982). The results of these experiments indicate that the use of sy
mmetry as an abstract concept: (a) depends on the type of stimuli used, and
(b) is not an easy task for pigeons.