Mice which had the opportunity to move around freely in simultaneously presented novel and familiar environments, did not display significant changes in plasma corticosterone levels nor in autonomic responses. In contrast, the signs of anxiety only appeared when mice were unable to regulate their own approach towards novelty, by preventing them from returning to their familiar compartment once they had freely entered the unfamiliar one, or by placing them physically into the novel compartment. These results demonstrate that contrary to the view generally encountered in the literature, anxiety, or fear, is not induced by novelty per se but when animals are artificially confronted novel stimuli and prevented from displaying normal neophobic responses.
Copyright © 1986. Published by Elsevier B.V.