Use of gesture sequences in captive chimpanzee (Pan troglodytes) play

This study examined the use of sensory modalities relative to a partner’s behavior in gesture sequences during captive chimpanzee play at the Chimpanzee and Human Communication Institute. We hypothesized that chimpanzees would use visual gestures toward attentive recipients and auditory/tactile gestures toward inattentive recipients. We also hypothesized that gesture sequences would be more prevalent toward unresponsive rather than responsive recipients. The chimpanzees used significantly more auditory/tactile rather than visual gestures first in sequences with both attentive and inattentive recipients. They rarely used visual gestures toward inattentive recipients. Auditory/tactile gestures were effective with and used with both attentive and inattentive recipients. Recipients responded significantly more to single gestures than to first gestures in sequences. Sequences often indicated that recipients did not respond to initial gestures, whereas effective single gestures made more gestures unnecessary. The chimpanzees thus gestured appropriately relative to a recipient’s behavior and modified their interactions according to contextual social cues.     

Interference between auditory and visual duration judgements suggests a common code for time

Auditory stimuli usually have longer subjective durations than visual ones for the same real duration, although performance on many timing tasks is similar in form with different modalities. One suggestion is that auditory and visual stimuli are initially timed by different mechanisms, but later converted into some common duration code which is amodal. The present study investigated this using a temporal generalization interference paradigm. In test blocks, people decided whether comparison durations were or were not a 400-ms standard on average. Test blocks alternated with interference blocks where durations were systematically shorter or longer than in test blocks, and interference was found, in the direction of the durations in the interference blocks, even when the interfering blocks used stimuli in a different modality from the test block. This provides what may be the first direct experimental evidence for a “common code” for durations initially presented in different modalities at some level of the human timing system.     

The impact of manipulating personal standards on eating attitudes and behaviour

The relationship between perfectionism and eating disorders is well established and is of theoretical interest. This study used an experimental design to test the hypothesis that manipulating personal standards, a central feature of perfectionism, would influence eating attitudes and behaviour. Forty-one healthy women were randomly assigned either to a high personal standards condition (n = 18) or to a low personal standards condition for 24 h (n = 23). Measures of personal standards, perfectionism, and eating attitudes and behaviour were taken before and after the experimental manipulation. The manipulation was successful. After the manipulation, participants in the high personal standards condition ate fewer high calorie foods, made more attempts to restrict the overall amount of food eaten, and had significantly more regret after eating than those in the low personal standards condition. Other variables remained unchanged. It is concluded that experimental analyses can be of value in elucidating causal connections between perfectionism and eating attitudes and behaviour.     

Perceived reachability in single- and multiple-degree-of-freedom workspaces

In comparisons of perceived (imagined) and actual reaches, investigators consistently find a tendency to overestimate. A primary explanation for that phenomenon is that individuals reach as a "whole-body engagement" involving multiple degrees of freedom (m-df). The authors examined right-handers (N = 28) in 1-df and m-df workspaces by having them judge the reachability of targets at midline, right, and left visual fields. Response profiles were similar for total error. Both conditions reflected an overestimation bias, although the bias was significantly greater in the m-df condition. Midline responses differed (greater overestimation) from those of right and left visual fields, which were similar. Although the authors would have predicted better performance in the m-df condition, it seems plausible that if individuals think in terms of m-df, they may feel more confident in that condition and thereby exhibit greater overestimation. Furthermore, the authors speculate that the reduced bias at the side fields may be attributed to a more conservative strategy based in part on perceived reach constraints.     

The relationship between work status congruence and work-related attitudes and behaviors

Research investigating differences in attitudes among full-time and part-time employees has a long history. Unfortunately, the empirical results have been mixed and conflicting. To resolve inconsistencies in prior research, the authors conducted 2 studies. In the 1st study, the authors developed a measure of work status congruence, which measures the degree to which employers match employee preferences for full-time or part-time status, schedule, shift, and number of hours. The authors hypothesized that a match or congruence between worker preferences and organizational staffing practices would be associated with positive employee attitudes and behaviors. In the 2nd study, the authors tested these hypotheses. The results indicate that work status congruence is positively associated with job satisfaction, organizational commitment, employee retention, as well as in-role and extra-role performance.     

The contribution of postural bias to lateral preferences for holding human infants

When asked to hold an infant, 60-85% of adults hold on their left, so that the infant's head is to the left of their midline (Brüser, 1981; de Chateau, 1983; Saling & Tyson, 1981). The same group bias has been found even when persons are merely asked to imagine holding an infant (Nakamichi & Takeda, 1995; Harris, Almerigi, & Kirsch, 2000). A number of variables have been found to contribute modestly to the bias, including the sex and handedness of the holder. In the current study, the role of a new variable is investigated, namely, the feeling of comfort for holding an infant on a particular side as indexed by one's foot preference for acts of stabilizing or postural support. To test this hypothesis, 282 right-handed college students (218 women, 64 men) were given the imagine-hold task along with 4 questions about their foot preference for posture and balance. The results showed that, at least for women, the two measures were modestly but significantly related.     

Effects of the testing situation on item responding: cause for concern

The effects of faking on personality test scores have been studied previously by comparing (a) experimental groups instructed to fake or answer honestly, (b) subgroups created from a single sample of applicants or nonapplicants by using impression management scores, and (c) job applicants and nonapplicants. In this investigation, the latter 2 methods were used to study the effects of faking on the functioning of the items and scales of the Sixteen Personality Factor Questionnaire. A variety of item response theory methods were used to detect differential item/test functioning, interpreted as evidence of faking. The presence of differential item/test functioning across testing situations suggests that faking adversely affects the construct validity of personality scales and that it is problematic to study faking by comparing groups defined by impression management scores.     

On the Complexity of Additive Clustering Models

Additive clustering provides a conceptually simple and potentially powerful approach to modeling the similarity relationships between stimuli. The ability of additive clustering models to accommodate similarity data, however, typically arises through the incorporation of large numbers of parameterized clusters. Accordingly, for the purposes of both model generation and model comparison, it is necessary to develop quantitative evaluative measures of additive clustering models that take into account both data-fit and complexity. Using a previously developed probabilistic formulation of additive clustering, the Bayesian Information Criterion is proposed for this role, and its application demonstrated. Limitations inherent in this approach, including the assumption that model complexity is equivalent to cluster cardinality, are discussed. These limitations are addressed by applying the Laplacian approximation of a marginal probability density, from which a measure of cluster structure complexity is derived. Using this measure, a preliminary investigation is made of the various properties of cluster structures that affect additive clustering model complexity. Among other things, these investigations show that, for a fixed number of clusters, a model with a strictly nested cluster structure is the least complicated, while a model with a partitioning cluster structure is the most complicated. Copyright 2001 Academic Press.     

The Korean diasporic experience: measuring ethnic identity in the United States and China

The measurement and development of ethnic identity of Koreans living in the United States and China were examined in the context of different migration experiences. Three hundred sixteen undergraduate college students were administered the Multigroup Ethnic Identity Measure (MEIM; J. S. Phinney, 1992). Separate principal-component analysis for each sample was performed to create cross-culturally equivalent Ethnic Identity and Other-Group subscales. Differential item function analysis revealed no cultural item bias among the retained MEIM items. Korean Americans had higher scores on the Ethnic Identity and Other-Group subscales and were more likely to be classified as bicultural than were Korean Chinese. Korean Chinese were more likely to be classified as assimilated, traditional, or marginalized in their cultural orientation.