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.     

A developmental-genetic analysis of aggressive behavior in mice (Mus musculus): III. Behavioral mediation by heightened reactivity or immobility?

This research was designed to investigate development and behavioral mediation in lines of ICR mice that have been selectively bred for aggressive behavior. General behavioral reactivity and behavioral immobility have been implicated as potential mediators by prior analyses of preattack interactions. To evaluate the separate roles of these dispositions, the emergence of attacks in genetically selected lines was tracked for 11 years by three levels of analysis: over successive generations, over development, and over dyadic interactions. Convergent outcomes were observed in all three levels with respect to two findings: (a) Robust line differences were obtained in attack behaviors, and (b) strong associations were found between line differences in attacks and line differences in behavioral immobility. Conversely, all three levels of analysis indicated a weak and inconsistent association between line differences in attacks and measures of social and nonsocial reactivity.     

Confidence in judgments based on incomplete information: An investigation using both hypothetical and real gambles

This study assessed how confidence in judgments is affected by the need to make inferences about missing information. Subjects indicated their likelihood of taking each of a series of gambles based on both probability and payoff information or only one of these sources of information. They also rated their confidence in each likelihood judgment. Subjects in the Explicit Inference condition were asked to explicitly estimate the values of missing information before making their responses while subjects in the Implicit Inference condition were not. The manner in which probability information was framed was also manipulated. Experiment 1 employed hypothetical gambles and Experiment 2 employed gambles with real money. Expressed likelihood of taking gambles was higher when probability was phrased in terms of '% chance of winning' rather than '% chance of losing', but this difference was somewhat less with real gambles than with hypothetical gambles. Confidence ratings in each experiment were actually higher on incomplete information trials than on complete information trials in the Explicit Inference condition. Results were related to the general issue of confidence in judgments.     

Cance and luck are not the same

In the mind of many people chance and luck act as real but different causes of events. Even in strictly defined situations as casino gambling, people may perceive influences of luck that help to overcome the negative expectancy defined by the rules of chance. Interviews with gamblers in casinos confirmed this idea. In two experiments it was established that the distinction between chance and luck are also made by ordinary subjects in everyday situations. The results revealed that chance is perceived to operate when an event is surprising, an unexpected coincidence. Luck is perceived when an event implies the escape from negative consequences, or the achievement of something that is important and difficult. The distinction between chance and luck can explain why people are trapped by the illusion of control, even when it is clear that they have no influence on the physical causation determining the outcomes of events. They cannot change the outcome of the roulette wheel, but they can employ their luck, which helps them to place their bets on the winning number.     

Recent developments in non-traditional employment testing: An introduction

The purpose of this special issue of theJournal of Business and Psychology is to provide a review and update of several key types of non-traditional employment tests. Non-traditional employment tests can be divided into two categories. One category consists ofbiological/physiological tests. The second category consists ofnarrow-based personality tests. A framework for thinking about non-traditional employment tests is provided.     

Effect of social support on the stress-burnout relationship

Business organizations have become interested in recent years in the role of social support in reducing the negative effect of stress. The purpose of this research is to examine the effects of two types of social support (i.e., job and life support) on the relationships between job and life stress and burnout. Participants consisted of 270 males and 254 females. For both males and females job stress and life stress correlate positively with burnout, while job and life support were negatively correlated with burnout. The hypothesis that social support would moderate stress-burnout relationships was not supported. Neither job support nor life support moderated job stress or life stress-burnout relationships. Females exhibited significantly higher levels of burnout, job stress, and life stress than males; however, there was no difference between males and females in the amount of social support received.     

Individual response profiles in the behavioral assessment of personality

A long-standing problem in the behavioural assessment of personality is the individual specificity of responses. Often, different persons externalize the same trait in different responses. One solution to this problem is to aggregate many different responses. The paper compares the power of response aggregation for predicting self-and other-ratings of personality with two alternative strategies of response selection: the nomothetic strategy of selecting the response with the highest overall predictive power, and the more idiographic strategy of selecting, for each individual, the most extreme response. Seventy subjects were videotaped in a sequence of social situations inducing shyness to various degrees. Five different nonverbal measures of shyness all correlated significantly with the subjects' self- or other-rated shyness, and showed low correlations across subjects and a substantial cross-situational consistency of response profiles. Response aggregation and both strategies of response selection were found to be equally powerful in predicting the subjects' self- and other-ratings of shyness from the five behavioural responses. Therefore, these findings somewhat dampen the hope often expressed in recent theoretical discussions of personality assessment that more respect for the individual case may improve nomothetic assessment procedures.     

Attitudes toward older and younger adults: a meta-analysis

Attitudes toward the elderly have been examined in a number of empirical studies, yet the question of whether the elderly are viewed more negatively than younger persons has not been resolved. A meta-analysis of the literature was conducted to examine this question; results demonstrated that attitudes toward the elderly are more negative than attitudes toward younger people. However, smaller differences between the evaluations of elderly and younger targets were found when (a) the study used measures of personality traits (compared with measures of competence), (b) there were a larger number of dependent measures included in the effect size, (c) specific information was provided about the target person (compared with when a general target such as old person was used), and (d) a between-subjects design (compared with a within-subjects design) was used. These results support Lutsky's (1981) conclusion that age, in and of itself, seems to be less important in determining attitudes toward the elderly than other types of information. The methodological limitations within the literature and a need to consider multiple components of attitudes toward older individuals are discussed.     

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.