A new type of soil material for a burrowing chamber for mice

We measure general activity of mice(Mus musculus) in a burrowing chamber from an ecological point of view. Natural topsoil or sand, however, is not suitable for long-term dwelling of mice, because burrows are likely to keep collapsing and to become rapidly rotten from being sprinkled with water to guard against collapse. For the present study, we devised a mixture of absorbent cotton and wood shavings as soil material. The mice burrowed in this soil just as they would in natural soil. About 10⁴ cm³ of the cotton-shavings soil were durable for at least 40 days with 3 mice. These results suggest that this soil material can be a useful tool in not only the study of general activity but also other studies (e.g., the observation of maternal behavior of mice in burrows).     

Colour versus quantity as cues in reverse-reward-competent squirrel monkeys (Saimiri sciureus)

To assess the relative salience of colour and quantity cues, squirrel monkeys previously trained to reach for the smaller of two quantities of food in a reverse-reward contingency task received colour discrimination training. After initial failure to discriminate between two colours of dots under a differential reinforcement regime, they learned the task when the S- colour was associated with zero reward. The monkeys then showed good retention on the original reverse-reward task of 1 versus 4 with pairs of dots presented in S+ or S- colours. However, on "mismatch" trials of 1S- versus 4S+ , only 2 of 4 monkeys tested showed a preference--1 monkey chose based on quantity, the other based on colour. Individual differences and the possible roles of overshadowing and blocking are discussed.     

Modeling support provision in intimate relationships

Whereas supportive interactions are usually studied from the perspective of recipients alone, the authors used a dyadic design to incorporate the perspectives of both provider and recipient. In 2 daily diary studies, the authors modeled provider reports of support provision in intimate dyads over several weeks. The 1st involved couples experiencing daily stressors (n = 79); the 2nd involved couples experiencing a major professional stressor (n = 196). The authors hypothesized that factors relating to (a) recipients (their requests for support, moods, and stressful events), (b) providers (their moods and stressful events), (c) the relationship (relationship emotions and history of support exchanges), and (d) the stressor (daily vs. major stressors) would each predict daily support provision. Across both studies, characteristics of providers, recipients, and their relationship emerged as key predictors. Implications for theoretical models of dyadic support processes are discussed.     

The Career Decision‐Making Process of Chinese American Youth

The authors investigated how negotiating two cultural expectations may influence the career decision‐making process of Chinese youth. In‐depth interviews were conducted with 8 participants addressing issues of role models, career interests, and individuals with whom they discussed career concerns. Consensual Qualitative Research (C. E. Hill, B. J. Thompson, & E. N. Williams, 1997) was used to analyze data. The findings suggest that parents' academic and career expectations influenced the career decisions of Chinese youth.     

Application of the behavioral investigative support system for profiling perpetrators of serial sexual assaults

The authors developed a data-based profiling system in order to support offender profiling. The system stored incident records of prior offenders. Inputting offence details of an unsolved incident, a probability score was assigned to each prior offender in the system; the score represented the behavioral similarity with the unsolved incident. The system then ranked all offenders in the system according to the probability scores, and prioritized the high-ranked offenders as possible suspects. Moreover, the system inferred the characteristics of unknown offenders by accumulating characteristics of the high-ranked offenders. The system achieved promising accuracy, especially for linking crimes to perpetrators. In 45 out of 81 simulation trials, the target offenders were retrieved as a rank score of 1 from among 868 sex offenders.     

Gaze alternation during “pointing” by squirrel monkeys (<Emphasis Type="Italic">Saimiri sciureus</Emphasis>)?

Gaze alternation (GA) is considered a hallmark of pointing in human infants, a sign of intentionality underlying the gesture. GA has occasionally been observed in great apes, and reported only anecdotally in a few monkeys. Three squirrel monkeys that had previously learned to reach toward out-of-reach food in the presence of a human partner were videotaped while the latter visually attended to the food, a distractor object, or the ceiling. Frame-by-frame video analysis revealed that, especially when reaching toward the food, the monkeys rapidly and repeatedly switched between looking at the partner’s face and the food. This type of GA suggests that the monkeys were communicating with the partner. However, the monkeys’ behavior was not influenced by changes in the partner’s focus of attention.     

Tobacco and alcohol tax relationships with suicide in Switzerland

Previous research has shown an empirical link between tobacco and alcohol use and suicide. If tobacco and alcohol use contribute to suicidal behaviors, then policies designed to reduce the tobacco and alcohol consumption may succeed in reducing suicides as well. To test this hypothesis, correlations for suicide rates with alcohol consumption, taxes on alcohol and tobacco in Switzerland were examined using sets of time-series data from Switzerland in 1965-1994. The tax on tobacco correlated significantly negatively with male standardized suicide rate. The tax on alcohol also correlated significantly with male standardized suicide rate in an autoregressive model. On the other hand, significant relationships with female suicide rate were not found. Policies designed to reduce tobacco consumption are consistent with a benefit of reducing suicides, particularly for men in this sample.     

Stereotype performance boosts: the impact of self-relevance and the manner of stereotype activation

The activation of positive stereotypes has been shown to produce academic performance boosts. Evidence regarding the role of self-relevance in producing such effects has been mixed. The authors propose that the subtlety of stereotype activation plays a key role in creating performance boosts among targets and nontargets of stereotypes. Study 1 found that subtle stereotype activation boosted performance in targets, but blatant activation did not. Study 2 was conducted on both targets and nontargets using different methods of stereotype activation. Again, targets showed performance boosts when stereotypes were subtly activated but not when they were blatantly activated. Nontargets, however, showed boosts in performance only when stereotypes were blatantly activated. The role of self-relevance in mediating sensitivity to stimuli is discussed.     

Perceptual completion in rhesus monkeys (Macaca mulatta) and pigeons (Columbia livia)

In a two-dimensional drawing, when the narrow edge of a bar appears to touch the edge of a large rectangle, humans overestimate the length of the bar (Kanizsa, 1979). Kanizsa has suggested that this illusion occurs because humans perceive the bar as continuing behind the rectangle and complete the "occluded" portion of the bar. Rhesus monkeys and pigeons were trained to classify black target bars with a variety of lengths as "long" or "short." In training, the bar was always located at the same distance from a gray box. After learning this discrimination, the subjects were tested on novel stimuli, in which the bar was located at three new locations. Monkeys showed a consistent response bias for "long" when the bar touched the box, but pigeons did not. Monkeys appear to have completed the "occluded" part like humans, whereas pigeons failed to do so. Because this procedure does not require animals to complete the "occluded" part with any particular form, their failure suggests that pigeons do not even perceive the target bar as continuing behind the "occluding" figure. The failure of pigeons may be due to difficulty in perceiving depth from two-dimensional drawings.