Response to Environmental Change: A Further Confirmation

Abstract

The response-to-change effect (1, 3 ) is a phenomenon relevant to our current studies of the antecedents of the differential problem-solving ability of Ss reared in free versus restricted environments (7) . If this is a real effect then we have added support for the importance of exploratory behavior in a maze which represents a marked increase in S's environmental complexity (2 ) . Fowler (4 ) has recently replicated Dember's (1) original findings, but on repeated occasions Levine (5, 6) has failed to do so. Hence, another study seemed warranted. Twenty mature experimentally naive Sprague-Dawley Ss from the Hollins College colony were used. The 7 males and 13 females were gentled for several days before the experiment. A Y-maze was employed which was 7 in. deep and 6 in. wide. The stem was 25 in. and the arms were 22 in. forming an angle of 50' with each other. The brightness of the arms could be made either black or white by inserting cardboard liners. As in Dember's experiment ( I ) , four conditions were called for. On Trial 1 the arms were either black-left and white-right or the reverse. Then on Trial 2 they were either both black or both white. Ss were assigned at random to one of the conditions with the exception that sexes were balanced as evenly as possible. On Trial 1 S was placed in the stem to explore for 15 min., but was prevented by hardware cloth partitions from entering either arm. S was then removed, the partitions were taken out, and the arms were changed to the same brightness. S was immediately replaced in the stem, and the arm entered was recorded. The changed arm was selected by 18 of the 20 Ss which is significant ( p = .001, using the sign test). No reasons for Levine's failure to obtain comparable results, except those already offered (4) , can be given.