Effect of concurrent visual feedback on acquisition of a weightlifting skill

Practice in front of a mirror is a common procedure for activities such as dance, gymnastics, and other sports. The purpose of this study was to examine the effect that performing with concurrent visual feedback from a mirror had on the acquisition of the power clean movement. 18 college-age males who had no prior experience with the power clean movement served as subjects who were assigned to one of two groups. One group had use of a mirror during the practice trials and the other practiced without the mirror. All subjects viewed an instructional videotape and had practice trials. All subjects were evaluated for proper technique on a pretest, a posttest without the mirror, and a posttest with the mirror. Analysis showed a significant difference between pre- and posttest performances for both groups and a significant difference between groups on the posttest performances with the mirror. Evidently the videotaped instruction was sufficient to allow both groups to improve in performance of the power clean. Differences in posttest performances with the mirror reflected the type of feedback (with or without the mirror) available during training.     

INDIVIDUAL AND SITUATIONAL CORRELATES OF WHISTLE-BLOWING

Although popular interest in whistle-blowing continues to increase, little is known about why some employees who observe wrongdoing report it, while others do not. In the present study, we analyze archival survey data from individuals who observed wrongdoing in any of 22 organizations. Results are generally consistent with predictions based on a model of whistle-blowing as a type of prosocial behavior. Whistle-blowing was more likely when observers of wrongdoing (1) held professional positions, (2) had more positive reactions to their work, (3) had longer service, (4) were recently recognized for good performance, (5) were male (though race was unrelated to whistle-blowing), (6) were members of larger work groups, and (7) were employed by organizations perceived by others to be responsive to complaints. Implications for research and practice are described.     

Sample size determinations for the two rater kappa statistic

This paper gives a method for determining a sample size that will achieve a prespecified bound on confidence interval width for the interrater agreement measure,. The same results can be used when a prespecified power is desired for testing hypotheses about the value of kappa. An example from the literature is used to illustrate the methods proposed here.     

Perceptions of speakers with minimal eye contact: Implications for stutterers

One hundred and thirty-three college students responded to percentage definitions of “good,” “minimal,” and “no” eye contact. They also judged their perceptions of a speaker with “little or no eye contact” on a semantic differential scale containing 60 polarized adjective pairs regarding personality traits. The majority of the student respondents defined an individual with “good” eye contact as looking at his/her audience/listener 90–100% of the time. This is a more stringent definition than other literature has indicated. Furthermore, speakers with little or no eye contact were judged less favorably on 70% of the items, which indicates that low eye contact adversely affects perceptions of a speaker's personality. Therefore, stutterers need to be made aware of the importance of and determinants of effective eye contact in communication. Also, the development of effective eye contact needs to be incorporated as a major goal in stuttering therapy.     

Interactions between area and numerosity

Summary The concept of filled area, i.e. the impressionistic ensemble of parts of a stimulus field occupied by dots, is used to account for various kinds of numerosity illusions due to perceptual interaction between a number of dots and their spatial arrangement. A measure of filled area is derived from a model for the perceptual clustering of dots on the basis of relative proximity. It is shown that the quantified concept of filled area successfully predicts illusion data from earlier studies. Subsequently, a two-alternatives forced-choice numerosity experiment is reported, the data of which gave further evidence of the predictive power of the filled-area hypothesis. Our approach is discussed with respect to spatial features of dot stimuli that might be in rivalry with the filled-area factor in numerosity-estimation tasks.     

Emotional sequelae of abortion: implications for clinical practice

For women in therapy who have had abortions, an exploration of the context and aftermath of each abortion has been suggested. This inquiry should include: characteristics of the woman herself before and at the time of the abortion, the nature of the interpersonal and cultural milieu at the time, characteristics of the medical environment and procedure, and any events subsequent to the abortion that may evoke regrets about the earlier decision.
Whether or not such an inquiry results in the identification of unresolved issues surrounding the abortion, it is likely to enhance one's general understanding of the client. Exploring a woman's decision to have an abortion can bring into relief developmental and family issues, relationship conflicts, and her aspirations for education, work, and family. A woman's approach to establishing and asserting her priorities and values in making difficult personal decisions becomes clear as does her ability to tolerate and resolve the ambivalence inherent in making difficult decisions.
In psychotherapy, it is important to understand and address those aspects of experience that women have difficulty resolving. Hence, the emphasis on categories of experience that may have a negative impact on a woman's emotional well-being after abortion. Nevertheless, the clinician should remember that even women who report negative post-abortion sequelae overwhelmingly report that they feel that the decision was the right one for them. Having ambivalent feelings to resolve does not necessarily mean that one has made a wrong choice, only that one has made an emotionally significant choice with far-reaching personal implications, in a sociocultural environment that reinforces the ambivalence inherent in such decisions.     

Reversal of genetic homeostasis in laboratory populations of Drosophila melanogaster under long-term selection for geotaxis and estimates of gene correlates: evolution of behavior-genetic systems

Among Drosophila melanogaster, divergently selected for geotaxis intermittently over 600 generations (28 years), about 80,000 animals have been analyzed behavior-genetically. Each major chromosome pair from two lines was isogenized on an unselected isogenic background. Measurement of their behavioral effects revealed the relative magnitudes II greater than III greater than X for the negatively geotactic (high) line and X greater than III greater than II for the positively geotactic (low) line. When reversing selection for the now phenotypically stable high and low lines and then repeatedly relaxing the reversals, a new genetic homeostasis in the low line was indicated by the return of the reversed-line average scores towards the low extreme; that is, the low line has attained a stable equilibrium for positive geotaxis, an uncharacteristic behavior and an effect not seen before 1979. This change suggests the recent evolution of a new coadaptation among genes. Although not as conclusive, a similar genetic interpretation is suggested for the high line.     

Advancing knowledge about delinquency and crime: The need for a coordinated program of longitudinal research

Past research on delinquency and crime has provided convincing data about correlates but not about causes, because it has been largely cross-sectional in design. Whereas cross-sectional research focuses on variations between subjects, longitudinal research can provide information about changes within subjects, which are more important for causes, prevention, and treatment. Many of the most important results in criminology have been obtained in longitudinal or experimental studies, and the major studies of these types are reviewed here. It is now desirable to combine the two methods in a new coordinated program of longitudinal studies including experimental interventions or quasi-experimental analyses. Such projects could study several overlapping cohorts, extend from birth to adulthood, have frequent data collection, and obtain data from a variety of sources about many different types of antisocial behavior.