Garvin McCain

Death rates, psychiatric commitments, blood pressure, and perceived crowding as a function of institutional crowding

The effects of crowding were examined in a prison system. Emphasis was directed toward three factors—social density (number of individuals in sleeping quarters), spatial density (space per person), and overall institutional population level. Archival data indicated that in prisons higher population years yielded higher death rates and higher rates of psychiatric commitments. Blood pressure measures were analyzed for inmates living in three types of housing that differed in degree of spatial and social density. Blood pressure was higher in more crowded housing. The degree of perceived crowding was more strongly related to space per person than number of occupants per housing unit.

The Relationship between Illness Complaints and Degree of Crowding in a Prison Environment

Illness complaint rates were examined in relation to degree of crowding in a federal prison and a county jail. It was found that dorm inmates in the prison had higher complaint rates than those in single cells. In the jail inmates in units of high spatial and social density had higher complaint rates than those in less crowded units. These findings suggest that crowding in prisons may induce psychological stress which can be reflected in an increased level of illness complaints.

Reward magnitude and instrumental responses: Consistent and partial reward

Two studies using partial or consistent large (500 mg) and small (45 mg) reward are presented. In both studies, after extended reward acquisition, differences are negligible or nonexistent. Results from the partial reward groups indicate extinction differences also disappear after extended training. These results do not seem to be in line with usual assumptions regarding the effects of reward magnitude.

A note on the use of prisons as environments for investigation of crowding

Some general considerations involved in studying the effects of crowding on humans are considered. It is proposed that prisons provide an excellent setting for such research since they contain a variety of realistically crowded conditions. The effects of spatial and social crowding are found to be separable in prisons.

Delay of reinforcement: Extended training and multiple shifts

Several lines of work involving reinforcement manipulations have produced early performance differences between differentially reinforced subjects. Late in training, these differences have disappeared. In the present study, similar effects were found using 10- and 30-sec delays of reinforcement. Delay shifts produced an NCE but no PCE. It is proposed that the late acquisition effects have not been considered in most learning models.

Procedurally related differences in the aggressive behavior ofBetta splendens (Regan)

The agonistic behaviors of maleBetta splendens (Regan) were studied during both mutually viewing and mutually caged encounters in an investigation of differences between these types of encounters. With the pairings of animals held constant, the experience of prior mutual viewing which produced significant habituation did not significantly alter aggression in subsequent mutually caged encounters. Furthermore, animals which exhibited submissiveness (zero display rates) during mutually caged encounters significantly increased the intensity of aggression during subsequent mutual viewing, while the dominant caged mates decreased the rate of displays. These results were interpreted to mean that mutual viewing produces habituation while mutual caging produces conditioned suppression, and that generalizations from one situation to the other may therefore be unwarranted.

The partial reinforcement effect after minimal acquisition: Single pellet reward, spaced trials

Achievement of a PREE following a small number of trials has posed a problem for several explanations of the PREE. The use of single or multiple pellets is also important to some of the explanations. In the present study the usual PREE was achieved using a single pellet and spaced trials.

Partial reinforcement with a small number of trials: Performance in extinction

Thirty-eight albino rats were given four acquisition trials in a straight alley. One group received 50%, the other 100% reinforcement. The 50% group was more resistant to extinction in terms of running times and latencies. This result was in accord with earlier work and is contrary to predictions from the frustration

Population density and nonaggressive competition

The Calhoun (1962) paper has become a keystone article for the population density literature. Although a few research reports have followed, several aspects of population density and the behavioral phenomena identified by Calhoun have been ignored. For example, the consummatory behavior in-aggregate property of the behavioral sink is an unstudied phenomenon. Furthermore, although the literature on potential population reduction mechanisms has grown rapidly, the mechanisms of pup mortality (cannibalization by adults) as identified by Calhoun has not been pursued systematically. Finally, the question of whether social or spatial density or other factors constitute the potent variables in the development of social pathology has not been tested directly. The purpose of these five related experiments was to investigate aspects of these behaviors.

Field Research on the Effects of Crowding in Prisons and on Offshore Drilling Platforms

Much of the contemporary interest in the possible psychological effects of crowding1 stems from the combined influence of Calhoun’s (1962) classic studies on crowding effects in animals and the concern about potential psychological consequences of human population growth. Calhoun’s work raised the possibility that humans might display behavior pathology similar to that observed in severely crowded rats. Increasing population growth offers the possibility that the degree of crowding that yielded behavior pathology in Calhoun’s studies may be approached or achieved by large segments of the world’s human population. Even now it is commonly assumed that existing degrees of crowding in urban areas contribute substantially to behavior pathology (Zlutnick & Airman, 1972).