Arousal as an explanation for differences in rats selectively bred for differential alcohol sensitivity

A common error made by behavior genetics researchers is breeding two lines for differences in central arousal rather than for a specific behavioral feature. Two lines of rats (Riley, Freed, & Lester, 1976) were selectively bred for locomotor impairment in response to a subhypnotic dose (1.5 g/kg) of ethanol. These lines (designated "most affected" and "least affected") were compared in a variety of tests and showed differences in a number of phenotypic traits in addition to locomotor impairment to ethanol. The published findings have been interpreted in light of a hypothesis suggesting adventitiously selected differences in central arousal between the two lines. This interpretation showed that their usefulness as animal models of alcoholism is seriously compromised.     

Category learning and change: differences in sensitivity to information that enhances or reduces intercategory distinctions

We examined the amenability of abstractions of categories to new and relevant information. In Experiment 1, Ss formed impressions of 2 sets of numbers by periodically estimating the cumulative means of each set. During the 1st half of the procedure, the 2 means were mathematically stable. During the 2nd half of the procedure, the mean of 1 set was modified and the mean of the other set remained unchanged. We predicted and found that the resultant estimates for the modified category changed more when the mean difference between the 2 categories was enhanced than when it was reduced. Experiment 2 suggested that the accentuation effect results from a 2-stage process of category learning (Stage 1) and category change (Stage 2). Experiment 3 replicated the effect with person categories. The relevance of category accentuation is discussed with respect to the modifiability of social beliefs.     

Intergroup aggression: its predictors and distinctness from in-group bias

Investigated predictors of intergroup aggression and its relations to in-group bias. In a questionnaire, 156 Israeli adults reported perceptions of their own religious group and of the ultraorthodox Jewish out-group and expressed aggression toward the ultraorthodox (opposing institutions that serve their needs, supporting acts harmful to them, and opposing interaction with them). Respondents showed in-group favoritism in trait evaluations, but this bias was unrelated to aggression. Perceived inter-group conflict of interests, the postulated motivator of aggression, predicted it strongly. The effects of conflict on aggression were partially mediated by 2 indexes of dehumanizing the out-group (perceived value dissimilarity and trait inhumanity) and by 1 index of probable empathy with it (perceived in-group-out-group boundary permeability). These variables related to aggression more strongly among persons who identified highly with their in-group. The variables also mediated the effects of religious group affiliation on aggression. The value dissimilarity finding supports derivations from belief congruence theory.     

Residential density and psychological health: the mediating effects of social support

People report excessive, unwanted social interactions, insufficient privacy, and are observed to be more socially withdrawn under crowded living conditions. If people socially withdraw from one another as a way to cope with crowding, this could lead to an unintended side effect of breakdowns in socially supportive relationships. A breakdown in socially supportive relationships could, in turn, account for some of the pathological consequences of chronic, high density living conditions. An empirical study of 175 male heads of household among inner city residents in India suggests that the adverse effects of residential crowding on psychological health are mediated by a breakdown of social support systems. The study also points to the value of examining social support as an endogenous variable in the stress and health process.     

Relation of sympathy and personal distress to prosocial behavior: a multimethod study

Assessed sympathy and personal distress with facial and physiological indexes (heart rate) as well as self-report indexes and examined the relations of these various indexes to prosocial behavior for children and adults in an easy escape condition. Heart rate deceleration during exposure to the needy others was associated with increased willingness to help. In addition, adults' reports of sympathy, as well as facial sadness and concerned attention, were positively related to their intention to assist. For children, there was some indication that report of positive affect and facial distress were negatively related to prosocial intentions and behavior, whereas facial concern was positively related to the indexes of prosocial behavior. These findings are interpreted as providing additional, convergent support for the notion that sympathy and personal distress are differentially related to prosocial behavior.     

The sensitivity of the Bender-Gestalt Test as a screening instrument for neuropsychological impairment in older adults

We investigated the sensitivity of the Bender (1938) Visual-Motor Gestalt Test (BGT) using the Halstead-Reitan Neuropsychological Battery (HRB) as the criterion for cortical dysfunction. We studied 95 subjects over age 55 who had been diagnosed as having dementia or pseudodementia. Subjects were classified as mild, moderately, or severely impaired on the HRB and as impaired or unimpaired on the BGT. The results indicated that the BGT is less sensitive (36%) than was expected when used on an impaired geriatric population. The data further indicated that false negatives occurred more frequently with the BGT when individuals had mild neuropsychological impairment. Less frequent misclassifications occurred as the severity of impairment on HRB indices increased.     

Psychometric properties of Loevinger's Sentence Completion Test in an adult psychiatric outpatient sample

Little research has been conducted on Loevinger's Washington University Sentence Completion Test of Ego Development in adult psychiatric outpatients. The measure is a promising method of assessing a construct of personality and character functioning that should be useful in research on psychopathology and in choosing treatment modalities. The data presented in this study address the question of the psychometric adequacy of the measure in this segment of the subject population. Specifically, estimates of interrater reliability, internal consistency, and test-retest reliability are presented for a sample of 42 adult outpatients. In addition, the relationship between total protocol ratings and item sum scores is explored.     

Backward walking: a simple reversal of forward walking?

The purpose of this study was to determine whether backward walking represented a simple temporal reversal of forward walking and, hence, could be controlled by a reversed cycling of the same group of neurons. Electromyographic (EMG), joint angle, joint moment, and joint muscle power patterns were compared for forward and backward walking, in 6 subjects. The joint angle patterns with the time-base of the backward walking reversed were similar, with the exception of the ankle. The moment patterns were similar except for the knee, whereas the joint muscle powers were almost reversed-polarity images of each other. This suggests that somewhat similar muscle activation patterns could be used to produce both modes of locomotion, but the temporal cycling of muscle contraction would be reversed: Concentric muscle activity in forward walking would become eccentric activity in backward walking, and visa versa. The EMG results generally supported these findings.     

Hypnosis, suggestion, and placebo in the reduction of experimental pain

Two experiments compared placebo and hypnotic analgesia in high and low hypnotizable subjects. Experiment 1 demonstrated that hypnotic and placebo analgesia were equally ineffective in low hypnotizables, but that hypnotic analgesia was much more effective than placebo analgesia in high hypnotizables. Experiment 2 replicated these results, but also included low and high hypnotizables who were given a nonhypnotic suggestion for analgesia. Both the low and high hypnotizables in this group reported greater suggested than placebo analgesia and as much suggested analgesia as high hypnotizable hypnotic subjects. Both experiments found substantial discrepancies between the amount of pain reduction subjects expected from the various treatments and the amount of pain reduction they actually reported following exposure to those treatments. In Experiment 2, subjects in all treatments who reduced reported pain engaged in more cognitive coping and less catastrophizing than those who did not reduce pain. Theoretical implications are discussed.