Evolution of kin recognition mechanisms in a fish

Animal Cognition - Both selection and phylogenetic history can influence the evolution of phenotypic traits. Here we used recently characterized variation in kin recognition mechanisms among six...     

The Fisher-Pitman permutation test when testing for differences in mean and variance

The Fisher-Pitman permutation test can detect any type of difference between two samples: hence, a significant Fisher-Pitman permutation test does not necessarily provide evidence for a difference in means. It is possible, however, to test separately for differences in means and variances. Here, we present a recently proposed two-stage procedure to decide whether there are differences in means or variances that can be applied when samples may come from nonnormal distributions with possibly unequal variances.     

Randomness and inductions from streaks: “Gambler’s fallacy” versus ”hot hand“

Sometimes people believe that a run of similar independent events will be broken (belief in thegambler’s fallacy) but, other times, that such a run will continue (belief in the hot hand). Both of these opposite inductions have been explained as being due to belief in a law of small numbers. We argue that one factor that distinguishes these phenomena is people’s beliefs about the randomness of the underlying process generating the events. We gave participants information about a streak of events but varied the scenarios in such a way that the mechanism generating the events should vary in how random the participants would judge it to be. A manipulation check confirmed our assumptions about the scenarios. We found that with less random scenarios, the participants were more likely to continue a streak.     

What makes a girl (or a boy) popular (or unpopular)? African American children's perceptions and developmental differences

Open-ended questions were used to obtain narrative accounts of what makes a girl (or a boy) popular (or unpopular) at school. The participants were 489 African American students in Grades 1, 4, and 7 recruited from high-risk inner-city neighborhoods. Appearance and self-presentation were mentioned the most in Grades 4 and 7. Prosocial characteristics were especially relevant for popularity in Grade 1, as were studentship in Grade 4 and peer affiliations in Grade 7. Deviant behaviors were nominated for popularity more frequently in Grade 7 than in the younger grades and more for boys' popularity than for girls'. The mean deviance scores were negative in all grade levels, suggesting a normative peer culture. Male groups in Grade 7 showed significant homophily in reports of deviant behaviors.     

Treatment choice for PTSD

The impetus for seeking help for assault-related difficulties often rests upon the victims themselves. Yet, we know very little about what factors influence a woman's decision to seek a particular kind of help after an assault. To learn more about these factors, data from 273 women with varying degrees of trauma history and subsequent PTSD symptoms were collected. All participants read a standard, "if this happened to you, what would you do" scenario describing a traumatic event and subsequent trauma-related psychiatric symptoms. Participants were given the same trauma scenario (i.e., sexual assault) and three treatment options to choose from: sertraline (SER), prolonged exposure (PE), or no treatment. Ratings of treatment credibility, personal reactions to treatment options, and treatment choice were examined. Women were more likely to choose PE than SER for the treatment of chronic PTSD. Perceived credibility of the treatment and personal reactions coincided with women's choices. By better understanding who would choose which treatments for PTSD and why, we will improve our ability to tailor how we approach discussing treatment options with these women.     

Callous-unemotional traits and developmental pathways to severe conduct problems

One method for defining pathways through which children develop severe conduct problems is based on the presence or absence of callous-unemotional (CU) traits. This study investigated potential differences between nonreferred children (mean age = 12.36 years; SD = 1.73) with and without CU traits (n = 98). Children with conduct problems, irrespective of the presence of CU traits, tended to have significant problems in emotional and behavioral regulation. In contrast, CU traits, irespective of the presence of conduct problems, were associated with a lack of behavioral inhibition. Hostile attributional biases were associated with conduct problems but only in boys and in the absence of CU traits. These findings suggest that the processes underlying deficits in emotional and behavioral regulation in children with conduct problems may be different for children with CU traits.     

Automatic activation of Yellow Peril Asian American stereotypes: effects on social impression formation

The authors randomly assigned 69 undergraduates to 1 of 2 perceptual priming conditions involving 80-ms flash words presented on a computer screen to activate information processing outside of conscious awareness. In the high-prime condition, the authors exposed participants to stereotype words associated with the Yellow Peril view of Asian Americans. The authors exposed participants in a low-prime condition to neutral words. All participants then read a vignette and evaluated its protagonist on several social dimensions. Results indicated that the priming procedure effectively biased participant evaluation of the vignette target, but only on items closely linked to Asian Americans. Contrary to predictions, however, participants in the high-prime group rated the target less Asian than did their low-prime group counterparts, an apparent reversal of the expected priming effect. The authors discussed theoretical implications.     

Priming effects on temporal order judgments about words: Perceived temporal priority or response bias?

In a temporal order judgment task, in which observers select which of two words appeared first, Stolz (1999) found that observers were more likely to select the word that had been semantically primed. Using repetition priming, we replicated Stolz’s finding and extended her results by demonstrating that the effect was due to both (1) repetition priming causing the primed item to be perceived as having occurred earlier and (2) a response bias to guess the repetition primed item as the correct response. We discuss our new finding that priming induces an attentional precedence effect in the context of previous research suggesting that exogenous spatial cuing induces an attentional precedence effect but identity or semantic priming may not.     

Self-Esteem, Teasing and Quality of Life: African American Adolescent Girls Participating in a Family-Based Pediatric Overweight Intervention

Two studies investigated overweight in African American girls. First, African American adolescent girls (BMI was ≥ 85th percentile) and their mothers participated in focus groups addressing weight and eating. Although mothers and daughters shared some similar views on these issues, there were important discrepancies, with mothers expressing greater doubt about the potential success of a healthy weight program. The second study evaluated baseline data from 39 African American girls participating in a weight management program; mothers' reports were also analyzed. In both studies, adolescents reported significant teasing, and in the second study, teasing was inversely associated with social quality of life (β=.55, t=3.01, p=.007). Motivation to participate was positively associated with teasing (r=.50, p < .01). Self-esteem was inversely related to positive health habits (all p < .05). Mothers who viewed their daughters as having higher self-esteem were less concerned about their daughters' weight. Differences in mothers' and daughters' perceptions highlight the importance of a family approach in pediatric overweight interventions. Results provide evidence that overweight African American girls face significant weight stigmatization and suggest areas to target regarding intervention implementation.