Categorical perception occurs in newly learned faces, other-race faces, and inverted faces

On the basis of findings that categorical perception (CP) is possible in complex visual stimuli such as faces, the present study tested for CP on continua between unfamiliar face pairs. Results indicate that CP can be observed for unfamiliar faces, in both familiar (same-race) and unfamiliar (other-race) groups. In addition, significant CP effects were observed in inverted faces. Finally, half-continua were tested where midpoint stimuli became endpoints. This was done to ensure that stimulus artifacts did not account for the observed CP effects. Consistent with the perceptual rescaling associated with CP, half-continua showed a rescaled CP effect. We argue that these CP effects are based on the rapid acquisition of perceptual equivalence classes.     

Peer functioning, family dysfunction, and psychological symptoms in a risk factor model for adolescent inpatients' suicidal ideation severity

Examined models of suicidal ideation severity that include two psychosocial risk factors (i.e., peer and family functioning) and four domains of psychological symptoms (i.e., generalized anxiety, depression, conduct problems, and substance abuse/dependence). Participants were 96 psychiatric inpatients (32 boys, 64 girls), ages 12 to 17, who were hospitalized because of concerns of suicidality. Adolescents completed a structured diagnostic interview, measures of suicidal ideation, and several dimensions of family and peer functioning. Results supported a model in which greater levels of perceived peer rejection and lower levels of close friendship support were associated directly with more severe suicidal ideation. In addition, indirect pathways included deviant peer affiliation and global family dysfunction related to suicidal ideation via substance use and depression symptoms. The results are among the first to demonstrate relations between suicidal ideation and several areas of adolescent peer functioning, as well as divergent processes for peer and family predictors of suicidal ideation.     

On the relationship between locus of control, level of ability and gender

In a sample of Norwegian 14- and 15-year-old students no significant relationship was found between total externality-internality score and level of ability. However, a significant relationship was found between ability and a subscale of locus of control related to degree of belief in the impact of school effort. The analyses of gender differences showed that girls had significantly higher total internal locus of control scores than boys. Boys were, however, significantly more internally oriented than girls on a subscale related to the respondents' general belief in luck, while girls were significantly more internally oriented than boys on a school effort scale. The present study does not support the notion that girls develop an attributional pattern which is more closely related to their abilities while boys may develop a broader attributional pattern.     

Ipsilateral loudness adaptation over multiple intensity levels

Could monaural loudness adaptation be a simple artifact of psychophysical contrast? From adaptation data based on the Ipsilateral Comparison Paradigm (ICP), A. J. Dange, J. S. Warm, E. M. Weiler, and W. N. Dember (1993) concluded that loudness adaptation was not an artifact of psychophysical contrast, but their conclusion was dependent on results from one intensity. This study, involving multiple intensities, re-examined the issue of contrast versus adaptation and generally supported the conclusions of Dange et al. The results also showed an unexpected asymmetry of adaptation based on the direction of the referent modulation used with the ICP technique. Some implications are discussed.     

Epidemiological personology: the unifying role of personality in population-based research on problem behaviors

Epidemiological personology refers to a paradigm in which a developmental perspective on individual differences is paired with a population-based sampling frame to yield insights about the role of personality in consequential social outcomes. We review our work in epidemiological personology, linking personality to diverse, problematic social outcomes: Mental disorders, health-risk behaviors, and violence. We conclude that broad-band personality measurement is both feasible and fruitful in large-scale research on problem behaviors, and we call for increased collaboration between personality psychologists and researchers in fields such as public health, epidemiology, and sociology.     

Searching for reliable relationships with statistics packages: an empirical example of the potential problems

Many social scientists appear to possess an overconfidence in the reliability of research results from a single, small-sample, inferential study. In this article, the authors speculate that "user-friendly" statistics packages have the potential to exacerbate statistical misinterpretation by providing researchers with a tool to explore data easily and identify what is interpreted as "reliable" relationships. This article contains an empirical demonstration of the potential problems that arise when a large number of statistical tests are interpreted. Results show that statistically significant results may be unreliable. Also, a zero relationship can erroneously appear as a medium to large effect size relationship when a small sample is used (e.g., n = 30). The authors suggest the need for multiple replications as the criterion of a reliable finding.     

Timeout postponement without increased reinforcement frequency

Three experiments were conducted to examine pigeons' postponement of signaled extinction periods (timeouts) from a schedule of food reinforcement when such responding neither decreased overall timeout frequency nor increased the overall frequency of food reinforcement. A discrete-trial procedure was used in which a response during the first 5 s of a trial postponed an otherwise immediate 60-s timeout to a later part of that same trial but had no effect on whether the timeout occurred. During time-in periods, responses on a second key produced food according to a random-interval 20-s schedule. In Experiment 1, the response-timeout interval was 45 s under postponement conditions and 0 s under extinction conditions (responses were ineffective in postponing timeouts). The percentage of trials with a response was consistently high when the timeout-postponement contingency was in effect and decreased to low levels when it was discontinued under extinction conditions. In Experiment 2, the response-timeout interval was also 45 s but postponement responses increased the duration of the timeout, which varied from 60 s to 105 s across conditions. Postponement responding was maintained, generally at high levels, at all timeout durations, despite sometimes large decreases in the overall frequency of food reinforcement. In Experiment 3, timeout duration was held constant at 60 s while the response-timeout interval was varied systematically across conditions from 0 s to 45 s. Postponement responding was maintained under all conditions in which the response-timeout interval exceeded 0 s (the timeout interval in the absence of a response). In some conditions of Experiment 3, which were designed to control for the immediacy of food reinforcement and food-correlated (time-in) stimuli, responding postponed timeout but the timeout was delayed whether a response occurred or not. Responding was maintained for 2 of 3 subjects, suggesting that behavior was negatively reinforced by timeout postponement rather than positively reinforced by the more immediate presentation of food or food-correlated (time-in) stimuli.     

Driving-induced stress in urban college students

Urban college student commuters (N = 407) were surveyed about their experiences with stress induced by driving. Of the participants 23.6% reported becoming angry at another driver more than once per day. They rated stress from other drivers as equal to the stress experienced during a college examination but gave slightly lower ratings to traffic congestion, road construction, and finding a parking place as sources of stress. Slow drivers, a child not restrained, and a vehicle following too closely were the highest rated annoying situations. Of participants, 21.6% had reported another driver to the police; nearly 22% said they carried a weapon for protection from other drivers (5.4% said a gun). Men were more than twice as likely as women to carry a weapon and three times as likely to carry a gun. Of the total sample, 19.1% feared being shot by another driver. Most participants (75.8%) said drivers were more aggressive and dangerous than they were five years ago.     

Attitudes about antidepressants: influence of information about weight-related side effects

Antidepressant drugs are frequently prescribed for women and have various side effects, including potential effects on body weight. This experiment examined the effects of information about the weight-related side effects of antidepressants on women's attitudes toward the drugs. 60 college women were randomly assigned to read about one of two drugs, fluoxetine (Prozac) or imipramine (Tofranil). Participants were either told or not told about veridical weight-related side effects, namely, weight loss for Prozac and weight gain for Tofranil. As hypothesized, weight-gain information lowered the personal acceptability of Tofranil, and weight-loss information enhanced the acceptability of Prozac. Although research with clinical populations is required, undergraduate women's decisions about the use of antidepressant medications may be influenced by societal body-image ideals.