In a bidirectional control procedure, rats had their first opportunity
to push a joystick immediately after observing, from an adjacent comp
artment, the joystick moving 50 times either to the right or to the le
ft, with each movement signalling the delivery of inaccessible food. H
alf of these animals observed the joystick moving automatically, and h
alf observed a conspecific demonstrator pushing the joystick. When the
y were given direct access to the joystick, the observers were rewarde
d for both left and right pushes. Rats that had observed the joystick
moving through the action of a conspecific demonstrator showed a respo
nse bias in favour of the observed direction of joystick movement (Exp
eriment 1), while rats that had observed the joystick moving automatic
ally, either in the presence or absence of a passive conspecific, did
not show observation-consistent responding (Experiments 1 and 2). Thes
e results apparently confirm that rats are capable of imitation or obs
ervational learning.