What do people think about changes in health behaviors? Differential perceptions of consequences of increases and decreases in health behaviors

Most health decision-making models posit that cost-benefit analyses underlie decisions to make changes in health-related behavioral practices. In a series of studies, participants imagined either increasing or decreasing the frequency of a variety of health behaviors and estimated the consequences of those changes. In Studies 1 and 2, individuals consistently estimated that increasing a health behavior produced greater consequences than did decreasing the behavior by an equivalent amount. The results of Study 3 demonstrated that this effect is due to differences in how individuals judge the impact of health behavior changes which involve not engaging in the behavior at all versus other types of changes. Taken together, these findings suggest that perceptions of the outcomes afforded by health behavior changes depend on both the behavioral frequency and direction of changes in behavior an individual is considering. This asymmetry has the potential to help explain patterns of behavior in a range of important health domains and may impact the effectiveness of behavior change interventions.     

歧视知觉对初中生的合作倾向与行为的影响

本文通过两个研究揭示歧视知觉对初中生合作倾向与行为的影响, 研究1采用问卷法对752名初中生进行为期一年的追踪, 运用潜变量交叉滞后结构方程模型分析歧视知觉与合作倾向之间的纵向预测关系; 研究2采用动态公共物品困境实验考察歧视知觉对合作行为的影响, 以及群体类型的调节作用。结果发现：(1)初中生的歧视知觉与合作倾向存在显著负相关; T1合作倾向可负向预测T2歧视知觉, T2歧视知觉可负向预测T3合作倾向; (2)在公共物品困境前三轮投资比和贡献率上, 歧视知觉和群体类型的交互效应显著; 而在后三轮仅发现歧视知觉在投资比和贡献率上的主效应, 以及群体类型在贡献率上的主效应。以上结果表明, 歧视知觉与合作倾向之间存在纵向螺旋式影响; 歧视知觉对前期合作行为的影响受到群体类型的调节, 但随着互动时间延长, 该调节作用消失。     

Egocentric search for disappearing objects in domestic dogs: evidence for a geometric hypothesis of direction

In several species, the ability to locate a disappearing object is an adaptive component of predatory and social behaviour. In domestic dogs, spatial memory for hidden objects is primarily based on an egocentric frame of reference. We investigated the geometric components of egocentric spatial information used by domestic dogs to locate an object they saw move and disappear. In experiment 1, the distance and the direction between the position of the animal and the hiding location were put in conflict. Results showed that the dogs primarily used the directional information between their own spatial coordinates and the target position. In experiment 2, the accuracy of the dogs in finding a hidden object by using directional information was estimated by manipulating the angular deviation between adjacent hiding locations and the position of the animal. Four angular deviations were tested: 5, 7.5, 10 and 15°. Results showed that the performance of the dogs decreased as a function of the angular deviations but it clearly remained well above chance, revealing that the representation of the dogs for direction is precise. In the discussion, we examine how and why domestic dogs determine the direction in which they saw an object disappear.