Social conditions during rearing are well known to affect adult alcohol consumption, but few experiments have explored the effects of social conditions on behaviors that are related to alcohol dependence, such as the persistence of alcohol seeking. This study compared the effects of isolation (ISO) and interaction (INT) rearing on the persistence of alcohol-seeking behavior. Rats were trained to lever press for a solution of 10% alcohol diluted in water. They were then exposed to a two-component multiple schedule of reinforcement (baseline). Responses in one component were reinforced by a higher rate of alcohol delivery (rich component, variable interval 15 s) and responses in the other component were reinforced by a lower rate of delivery (lean component, variable interval 45 s). The persistence of lever pressing in the presence of each stimulus was then assessed during extinction. The results from baseline showed that response rates in rats in both groups were higher in the rich component than in the lean component, but ISO rats responded significantly more than INT rats in both components. The persistence of responding during extinction in ISO rats in both components was also higher than that in INT rats. The results show that effects of ISO are not restricted to alcohol consumption, but also affect persistence of alcohol-seeking behavior, which may reflect differences in the value of drug-related stimuli.

This study analyzed choice behavior in the Hungry Donkey Task, with a focus on learning trajectories and the stability of preference, in 100 children of different ages (8-9, 10-11, 12-13, 14-15, and 16-17 years old). The results indicated that (a) learning occurred as the task progressed, (b) early adolescents performed poorly during the task, and (c) most of the participants did not reach the stability criterion during the task. The present study suggests that decision-making in children and adolescents varies with age, and that the inclusion of an operant-based approach (e.g., the use of stability criterion) may improve methods for evaluating decision-making in children.

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This research aimed to experimentally explore how rats reared in environmental enrichment (EE) and in isolation (ISO) behave in the prosocial behavior liberation task. The subjects were reared in two conditions: EE and ISO, and then submitted to the task. The results suggests that EE subjects spent more time near the restrainer, displayed faster door-opening behavior but interacted less with the released conspecific task compared with the ISO subjects. Our preliminary findings suggest that the rearing conditions may affect prosocial behavior, and that EE may increase the probability of displaying prosocial behavior. We discussed the need of more studies about the effect of rearing conditions and how it may impact motivations associated with the prosocial behavior and its consequences.

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Social conditions have been proposed to play a significant role in determining alcohol dependence, but no consensus has been reached regarding the circumstances under which social interaction influences alcohol intake. Studies with animal models that investigate the effects of social conditions on alcohol consumption have reported mixed results. In the present review, we intended to identify procedural variables that may explain differences among experiments. Separately, we analyzed features of isolation and group-housing conditions that might influence the effects of social conditions on alcohol consumption. For each condition, some variables were found to influence alcohol consumption. In isolation studies, variables such as age at isolation, age at alcohol intake, and length of isolation have been shown to alter alcohol intake. Studies that have focused on social interaction showed that such factors as group size, environmental enrichment, and the context of self-administration affect consumption in group-housed rats. The studies reviewed herein indicated that several elements of social conditions—and numerous interactions between them—influence drinking behavior. Systematic evaluations that isolate the effects of each variable are necessary to better understand the effects of the interplay between biological and environmental factors on alcohol consumption.

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