Group Commitment and Resource Conservation: Two Field Experiments on Promoting Recycling1

Two experiments evaluated the effect of commitment on paper recycling. Using an ABA design, Experiment 1 asked 24 individuals in a retirement home to sign a 4-week group commitment pledge to recycle paper. During this intervention, the subjects recycled 47% more paper than they had during baseline. They continued to recycle at this level during a 4-week follow-up period, when the group commitment was removed. Experiment 2 evaluated the relative effectiveness of group commitment, individual commitment, and token reinforcers on paper recycling in a college dormitory. The students in all three experimental conditions recycled from three to five times more paper than those in the control group during the 4-week intervention. However, in the 3-week follow-up period, when the treatments were removed, only the individually committed subjects continued to recycle significantly more paper than the controls.     

Contributors to the Appraisal of Major Life Changes: Gender, Perceived Controllability, Sensation Seeking, Strain, and Social Support

This study investigated relationships between the appraisal of life events and gender, locus of control, social support, strain, and sensation seeking. In group sessions, undergraduate males and females completed self-report measures assessing life events appraisals and self-report measures for the above individual differences. Analyses supported the notion that a range of these variables, previously shown to serve as moderators of life stress, are significantly related to the appraisals of life events. Moreover, in addition to the gender differences obtained for the perception of life events, gender was found to influence several associations between the individual differences and life events appraisal.     

Personality Correlates of Confidence in One's Decisions

ABSTRACT Taylor and Brown (1988) hypothesized that certain illusions, such as unrealistic optimism, are predictably associated with positive affect, social skills, and intellectual functioning. To test this hypothesis, we obtained data from 162 students who first filled out a questionnaire containing dispositional measures of affect, social skills, and approaches to problem solving; in a second session they completed three tasks requiring difficult decisions, reporting their confidence in each decision. Accuracy of judgments was found to vary considerably from task to task, but confidence ratings showed a consistent pattern of individual differences. This result lent support to Taylor and Brown's hypothesis, as did other features of the data, most notably several small but significant Pearson r s between confidence ratings and dispositional variables. Removing the effects of accuracy from these r s reduced their magnitude very little; it yielded partial r s interpretable as evidence that illusory confidence is associated with personality traits which, in this case, load saliently on factors labeled ( a ) affective, and ( b ) cognitive/social.     

Genetic and environmental variation on the California Psychological Inventory vector scales

Three recently introduced vector scales for the California Psychological Inventory (CPI) were scored for the National Merit Twin Sample and subjected to a heredity-environment analysis. Confidence intervals for genetic and environmental parameters were obtained by a bootstrap method. Two of the scales, Internality (Vector 1) and Self-Realization (Vector 3), showed the substantial heritability and near-zero family environment effects typically found for personality scales, whereas Norm-Favoring (Vector 2) showed an appreciable effect of family environment and a nonsignificant heritability.     

Effects of alternate modes of administration on Rorschach performance of deaf adults

This study examined two modes of administering the Rorschach Inkblot Technique to determine which was more appropriate for a college-educated, deaf population. Twenty-four prelingually deaf adults took the Rorschach in sign language and in written English, using a counterbalanced test-retest design, and their sign and written scores were compared to each other and to 1986 norms for Exner's Comprehensive System. Seventeen variables measuring such areas as perceptual accuracy, perceptual complexity, and self-focus were found to vary more than one standard deviation from Exner's norms. Differences between sign and written conditions on several affective variables were found. Written administration can be used by examiners who are informed about deafness and aware of variables that may be underreported by written inquiry.     

Using the Millon Clinical Multiaxial Inventory's Scale B and the MacAndrew Alcoholism Scale to identify alcoholics with concurrent psychiatric diagnoses

The ability of the MacAndrew Alcoholism Scale (MAC) and Scale B of the Millon Clinical Multiaxial Inventory (MCMI) to discriminate independently defined alcoholics with psychiatric diagnoses from other psychiatric patients was examined for males and all alcoholics, using three different criteria of alcoholism. The MAC identified from 80% to 87% of male alcoholics and 76% to 82% of all alcoholics, and from 25% to 52% of male nonalcoholics and 55% to 75% of all nonalcoholics, resulting in a large number of false positives. Scale B identified from 31% to 60% of male alcoholics and 33% to 43% of all alcoholics, and from 73% to 85% of male nonalcoholics and 85% to 94% of all nonalcoholics. The operating characteristics of Scale B showed that it was not as efficient in identifying alcoholics as previous work had indicated. We suggest that Scale B should not be used and the MAC should be used cautiously to discriminate alcoholics with psychiatric disorders from patients without alcoholism.     

Effects of alcohol and extended practice on divided-attention performance

The effects of alcohol and extended practice on divided attention were investigated using a visual tracking task and an auditory detection task. Subjects performed the tasks with and without alcohol, under single-task (S) and dual-task (D) conditions, both before and after they had received extended practice under single-task conditions without alcohol. Tracking accuracy improved with practice and was impaired under divided-attention conditions but was not affected by alcohol. Speed of detection was impaired by alcohol, improved by practice, and impaired by divided attention. Extended practice did not reduce the influence of alcohol. The effects of both alcohol and practice on speed of detection were significantly greater under dual-task conditions than under single-task conditions. Analysis of detection-task reaction times in terms of relative divided-attention costs, (D-S)/S, showed no effect of alcohol, but a highly significant reduction in costs with extended practice. It is concluded that (1) alcohol and practice can have quantitatively, but not qualitatively, similar effects on speeded performance, and (2) the effect of alcohol is not influenced by the attentional requirements of the task.     

The relation between color spreading and illusory contours

In the present study, we examine the relation between neon color spreading (Redies & Spillmann, 1981) and illusory contours. In Experiment 1, the effects of misalignment between the line elements on the illusory contours in the Ehrenstein figure and in the Redies-Spillmann figure were examined. The remarkable overlap of the two curves for the likelihood of perceiving illusory contours in the Ehrenstein figure and in the Redies-Spillmann figure suggests that the illusory contours surrounding brightness enhancement (Ehrenstein, 1941) and those surrounding neon color spreading are caused by the same mechanism. We further examined both the effects of the interposed grids seen either in front of or behind the figures (Experiment 2) and the effects of misalignment (Experiment 3) on the illusory contours and range of color spreading, and found a high correlation between the appearance/disappearance of illusory contours and global/local color spreading. In Experiment 4, we added new lines to induce illusory contours to the line elements inducing local color spreading. We found that global color spreading was seen to cover the area surrounded by the illusory contours. On the basis of these findings, we suggest that there is an interaction between illusory contours and local color spreading.     

Monocular stereopsis with and without head movement

Random dots moving with various velocity gradients were presented to observers; the motion was yoked to head movement in one condition and to no head movement in another. In Experiment 1, 12 observers were shown motion gradients with sine, triangle, sawtooth, and square waveforms with amplitudes (equivalent disparities) of 12' and 1 degrees 53'. In Experiment 2, 48 observers were shown only the sinewave or square-wave gradient of 1 degrees 53' disparity either with or without head movement so that the observers' expectation to see depth in one condition did not transfer to another. The main findings were: (1) with 12' disparity, the head-movement condition produced perceived depth but almost no perceived motion, whereas the no-head-movement condition produced both perceived depth and perceived motion; (2) with 1 degrees 53' disparity, both conditions produced perceived depth and perceived motion; and (3) when the expectation to see depth was removed, the no-head-movement condition with the square-wave gradient produced no perceived depth, only motion. We suggest that monocular stereopsis with head movement can be achieved without perception of motion but monocular stereopsis without head movement requires perception of motion.