The various changes in mood and behavior that may occur in patients treated with adrenocorticotrophic hormone (1,6) have made it pertinent to assess the effect of exogenous ACTH on behavior motivated by noxious stimulation. That some effect of ACTH on avoidance conditioning does occur is revealed in studies discussed by Mirsky, Miller, and Stein (5).In avoidance conditioning the animal must respond appropriately to the conditioned stimulus in order to prevent the occurrence of the painful unconditioned stimulus. Consequently, it may be postulated that any modification of the response to a noxious stimulus would be reflected in avoidance conditioning. METHOD SubjectsThirty-one male Wistar rats 100 to 120 days old were used. The Ss were maintained on an ad libitum supply of food and water throughout the experiment. The animals were randomly assigned to the experimental conditions. A pparatusThe tests were conducted in a two-compartment apparatus. The unit was 23 in. long, 7 in. wide, and 9 in. high. A 2-in. barrier of stainless steel liars % in. in diameter, l^ in. apart, separated the two compartments. The top bar of the barrier was mounted on bearings to prevent perching. The floor was a grid of stainless steel rods identical in size and spacing to those described for the barrier. The two ends and the top were made of wood, and painted while inside. One side consisted of a sheet of white milk glass. Illumination was provided by two 25-w. bulbs located behind this translucent glass. The remaining side consisted of two pieces of plain glass with a black cloth inserted between them. This made it possible to observe the animal without the distraction of movements by E.A push-button switch activated a buzzer and a timedelay relay that automatically delivered a shock to the animal after S sec. if it failed to respond (110 v. with 85,000 ohms in series with the animal). Another push-

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Dramatic changes in individual and group behavior have been reported in studies of experimentally induced "neurotic behavior." (iantt has observed such phenomena in his dog, Nick (2). Liddell made similar observations with sheep (3), and Masserman has reported extensive behavioral changes in cats (4) and monkeys (5). Although many investigators have been aware of changes in the social interactions of animals after a series of conditioning experiences, it is noteworthy that no controlled experiments on inlerindividual conditioning have been reported.Laboratory studies of avoidance conditioning typically have been restricted to conditioned stimuli such as lights and tones. It is not, however, an inherent aspect of the phenomenon which imposes this restriction. The present study was designed to demonstrate that one monkey can be successfully utilized as the stimulus for conditioned avoidance behavior in other monkeys. The specific aim was to develop a technique which could be used to modify interanimal transactions. The demonstration of such a possibility is considered relevant to numerous problems in the area of group functioning and personality theory. This lack of application of conditioning principles to social interaction phenomena is particularly interesting when one recognizes the importance of interindividual transactions in clinical practice. METHOD SubjectsSixteen rhesus monkeys were utilized in the experiment. One (no. 77) was used as the conditioned stimulus. Seven (62, 71, 72, 75, 76, 78, and 8t) constituted the group to be conditioned. Eight additional animals (53, 54, 55, 56, 57, 58, 60, and 61) were used to test for stimulus generalization and to establish a discriminated conditioned response. Of the 16 animals no. 60, 61, and 78 were females. The conditioning animals were employed a year before as .S' s in a preconditioning study

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Consistency of individual performances is an important requirement for most dependent variables. If one measures performance on a relatively unreliable test, the probability of obtaining significant results attributable to the effects of an independent variable is poor. Lack of internal consistency in the dependent variable leads, in general, to an underestimate of the action of an independent variable. In the investigation of learning, however, a constant level of performance scores is neither expected nor desired. By definition, changes in performance are expected between repeated tests or trials. When a learning task is employed as a measure, the more sensitive task is the one on which 5s' ranks remain relatively constant from trial to trial or from one stage of learning to another. A task on which ,5*3 vary widely in rank position from one stage of learning to another will be an insensitive indicator of the action of an independent variable.Carr (2, 3) has emphasized some of the practical and theoretical hazards that often occur in interpreting learning task reliabilities; however, if precautions are taken, the reliability figures undoubtedly contribute materially to the use of the task in question. In addition, the availability of reliability coefficients makes it possible to assess the effects of minor changes in the apparatus. For example, both Leeper (8) and Ruch (10) have demonstrated the increased reliability of animal mazes when retrace doors are added. McNemar (9, p. 122) has discussed the problem of the meaningfulness of reliability determination for learning tasks.The aim of the present investigation was to determine the reliability characteristics of the object-quality discrimination task in order to improve the usefulness of the test as a dependent variable.