Defensive reactions of “wild-type” and “Domesticated” wild rats to approach and contact by a threat stimulus

Selective breeding of wild rats over many generations on the basis of low or high defensive threat and attack to human approach and contact has produced highly polarized “domesticated” and “wild-type” animals. Because the selection procedure selectively involves these two defense patterns, and these clearly differ in the two groups, it is of interest to determine if other, nonselected, defensive behaviors to threat stimuli also change. “Domesticated” and “wild-type” rats of the thirty-fifth generation were run in a fear defense test battery (F/DTB) to systematically evaluate defensive behaviors to a variety of present threat stimuli. “Domesticated” rats showed reduced avoidance and slower flight speed to an approaching experimenter, reduced jump/startle response to handelap and dorsal contact, less vocalization and boxing to vibrissae stimulation or to an anesthetized conspecific, and reduced defensiveness to an attempted pickup by the experimenter. These results indicate that selective bi-directional breeding for defensive threat and attack to human approach and contact produces group differences in a variety of defensive behaviors, and in defensiveness to stimuli other than those on which the selection was based. © 1994 Wiley-Liss, Inc.     

Interval estimation for linear functions of medians in within-subjects and mixed designs

The currently available distribution-free confidence interval for a difference of medians in a within-subjects design requires an unrealistic assumption of identical distribution shapes. A confidence interval for a general linear function of medians is proposed for within-subjects designs that do not assume identical distribution shapes. The proposed method can be combined with a method for linear functions of independent medians to provide a confidence interval for a linear function of medians in mixed designs. Simulation results show that the proposed methods have good small-sample properties under a wide range of conditions. The proposed methods are illustrated with examples, and R functions that implement the new methods are provided.     

Hungry people prefer larger bodies and objects: The importance of testing boundary effects

Several lab-based studies have indicated that when people are hungry, they judge larger women's bodies as more attractive, compared to when they are satiated. These satiety-dependent judgements are assumed to provide explanatory power when it comes to the noted cross-cultural differences in attitudes towards women's adiposity, whereby people who live in regions that are under greater nutritional stress tend to have more favourable attitudes towards bigger bodies. However, it is premature to assume that women's bodies are the proper or actual domain of the satiety-dependent judgement shifts found within research study testing contexts until stimuli other than female bodies have also been tested: The research programme falls into the trap of confirmation bias unless we also seek out disconfirmatory evidence and test the boundaries of the effects of hunger. Accordingly, we collected attractiveness judgements of female and male bodies manipulated to vary in size by varying level of adiposity, and objects manipulated to vary in size, from 186 participants who also reported their current hunger level. We found that larger sizes of stimuli in general, and women's bodies in particular, especially when judged by women, were judged as more attractive by the hungrier participants. We discuss these patterns in the context of the Insurance Hypothesis, the Environmental Security Hypothesis, and the impact of hunger on acquisition.     

Assessment to identify learner-specific prompt and prompt-fading procedures for children with autism spectrum disorder

Few studies have evaluated the use of assessment to identify the most efficient instructional practices for individuals with autism spectrum disorder. This is problematic as these individuals often have difficulty acquiring skills, and the procedures that may be efficient with one individual may not be for others. The experimenters conducted instructional assessments to identify the most efficient prompt type (model, partial physical, full physical) and prompt-fading procedure (progressive delay, most-to-least, least-to-most) for teaching auditory–visual conditional discriminations for individuals with autism spectrum disorder. Each assessment was conducted at least twice, and a final generality test combined the most and the least efficient prompt type and prompt-fading procedure for teaching novel auditory–visual conditional discriminations. The results demonstrated learner-specific outcomes for the prompt type assessment, whereas the least-to-most prompt fading procedure was most efficient for all participants.     

Evaluating preference for and reinforcing efficacy of fruits and vegetables compared with salty and sweet foods

Children diagnosed with autism spectrum disorder are often more selective in their food preferences than their typically developing peers. Additionally, many preferred food selections have minimal nutritional value. We evaluated the preference for, and reinforcing efficacy of, fruits and vegetables compared with salty and sweet foods, which are often used as edible reinforcers. Multiple-stimulus preference assessments were conducted to identify preferred foods, and reinforcer assessments were conducted to determine the reinforcing efficacy of more preferred foods. Fruits and vegetables were sometimes preferred over salty or sweet foods and often functioned as reinforcers. Future research should incorporate fruits and vegetables into preference assessments when identifying putative reinforcers.     

Cumulative consequences of stigma: Possessing multiple concealable stigmatized identities is associated with worse quality of life

Large health disparities exist between stigmatized and nonstigmatized groups. In addition to experiencing and anticipating greater discrimination, members of stigmatized groups also tend to demonstrate greater ruminative tendencies in response, which may lead to these poor health outcomes. Even among stigmatized groups, differences in the visibility of stigma lead to different mechanisms through which stigma takes its toll. Previous work has primarily focused on the impact of belonging to a single marginalized group; however, people often belong to multiple marginalized groups, and this likely affects both their health outcomes and their anticipation of stigma. In the current study, we focused on individuals with concealable stigmatized identities (CSIs)—socially stigmatized identities that are not immediately apparent to others—and created a measure of concealable marginalization that captures multiple group memberships. We predicted that those possessing a greater number of CSIs would anticipate more stigma from others, and, in turn, ruminate more about the stigma, which would negatively impact the health. Surveying N = 288 adults with CSIs, we found that possessing a greater number of marginalized concealable identities predicted worse self-reported physical quality of life. These relationships were partially mediated by greater anticipated stigma and brooding rumination in regard to their CSI. This work illuminates a more complete picture of how living with CSIs can take its toll on health.