“…Punishment has been found to affect different measures of learning. In many studies, in which responses are scored as either right or wrong, punishment has led to a decrease in the number of errors (10,13,24,25,26,27,36,41,54,55,56,57,79,80,87,111,116,137,138,172,173,193,196,199,200,201,202,204,206,218,301,302,307,326). When speed of learning is measured in terms of the number of trials required to reach criterion, we find that punishment often results in a smaller number of trials (19,24,25,26,27,36,41,54,55,111,137,155,171,193,…”