Comments by the Discussant

The Psychological Record -     

Effects of stimulus preexposure on omission responding and omission-produced dishabituation of the human electrodermal response

As a test of Wagner's (1981) theory of habituation, three experiments examined the effects of stimulus preexposure on electrodermal responding to the absence of a stimulus and on omission-produced dishabituation. The general procedure for all experiments consisted of a preexposure phase in which one stimulus (S1) was presented 20 times, followed by a pairing phase in which S1 was followed by a second event, S2. After a number of S1-S2 pairings, S2 was omitted for one trial and was then represented following S1 on the next trial. Electrodermal activity was measured in all experiments, and in Experiments 2 and 3, a measure of expectancy of S2 in the presence of S1 was also obtained to provide a putative index of S2 priming by S1. Experiments 1 (N=48) and 2 (N=72) employed 15 S1-S2 pairings prior to S2 omission. Significant omission responding and dishabituation to S2 were obtained in both experiments. However, omission effects were not influenced by preexposure presentations of S1. Experiment 3, on the other hand, demonstrated that omission responding and dishabituation were attenuated by 20 preexposures of S1 when only 4 S1-S2 pairings were employed. In addition, Experiments 2 and 3 revealed that although expectation of S2 developed as a function of S1-S2 pairings, it too was reduced by preexposure to S1. Only Experiment 3 provided preexposure effects that are consistent with Wagner's (1981) theory.     

Do Temporary Workers Always Lower Workgroup Effectiveness? The Moderating Effect of Job Similarity in Blended Workgroups

Workgroups containing both permanent and temporary workers are often referred to as being ‘blended’. There exists a general view in the literature that workgroups blended in this way function less well with greater rather than fewer temporary workers. However, this notion has received little direct testing. Drawing on social identity theory and the input-process-output model of group effectiveness, this study examines the performance of 131 workgroups containing varying proportions of temporary agency workers, along with the proposed group processes: distributive justice climates reported by permanent and temporary workers and altruistic behaviors from permanent to temporary workers and vice versa. We find that blended workgroups with a greater proportion of temporary workers do not exhibit poorer justice climates, altruism, or performance; the hypothesized negative effects only emerge when jobs performed by temporary and permanent workers within the workgroup are highly similar. Counter to expectations, a positive indirect effect between proportion of temporary workers to workgroup performance via altruism from permanent to temporary workers was found when job similarity is low. Theoretical and practical implications are considered, focusing on the importance of managing social identity threat in blended workgroups.     

Young children's understanding of displaced aggression

According to previous research, young children do not understand displaced aggression. The present study examines the early phases of the understanding of the causes of moderately and extremely displaced aggression. Preschool and kindergarten children (3 to 5 years of age) viewed eight videotaped episodes of displaced aggression. Their comprehension of this aggression was assessed by means of open ended questions and forced choice picture selections. By age 5 most children had some understanding of displaced aggression, but this understanding was not complete. The early understanding revealed in the present study may be due to the use of short, simple realistic videotaped episodes appropriate for the limited processing abilities of young children. Extreme displacement was not more difficult to understand than moderate displacement.