SOME OBSERVATIONS ON AN OPERANT IN THE OCTOPUS

Abstract

Operant behavior has been successfully demonstrated in all species of mammals and birds for which a serious attempt has been made. Comparatively little attention has been paid to invertebrate species. This paper reports preliminary exploration of the behavior of the octopus (O. vulgaris. Lamark) to see whether components of its behavior could be found which fulfill the definitive requirements necessary to identify them as operants. The octopus has the advantage over most invertebrate species in that it has well-developed motor behavior of a nature which makes the selection of an arbitrary, objectively recorded response quite easy. In addition, Young and Boycott (1955) describe behavior in the octopus which is almost certainly operant in nature, i.e., not elicited, but maintained by its consequences. One reason for interest in this problem is that the octopus belongs to a phylum (Molusca) which has evolved independently of the pathway which leads to the vertebrates since Cambrian times (some 500 million years ago). If the phenomena of operant behavior are to be found in the octopus as well as in the vertebrate species studied, then these phenomena probably are of very general biological significance. Three octopuses have been studied. All three were trained to pull a lever which led to the delivery of food. In two, reasonably consistent lever-pulling behavior was maintained until extinction; only partial success was obtained with the third octopus.