Level of instigation and model similarity as determinants of aggressive behavior

A study was conducted to replicate and extend a finding by Wheeler and Levine [1967] indicating that a dissimilar model was more effective in inducing the contagion of aggression than a similar model. On the basis of recent findings suggesting the circumstances under which dissimilar others are more influential than similar others, the following predictions were derived: When subjects are highly instigated, dissimilar models can influence subjects to be more aggressive than can similar models; when subjects are under a low degree of instigation similar models will influence subjects to be more aggressive. Subjects presented their point of view on a case study in a three-person group discussion setting. Then subjects heard the second person (instigator) attack their position in a highly abusive or slightly abusive manner (High vs Low Instigation). Next subjects heard a third person, whom they had been led to believe was similar or dissimilar to themselves, attack the instigator (Similar vs Dissimilar Model). Finally subjects had an opportunity to express their feelings to the instigator. The results supported the predictions.     

Belief similarity and attitude similarity as determinants of interpersonal attraction

It was predicted that attraction would be a function of both attitude similarity and belief similarity, but that attitude similarity would have the greater influence. In Expt I, 60 subjects were presented with strangers that were either similar or dissimilar on attitude and on belief. Attraction was a positive function of both attitude similarity (p < .05) and belief similarity (p < .01). Experiment II replicated and extended Expt I with the addition of a 50% similar group for both attitude and belief. Attraction was a positive linear function of both attitude similarity (p < .001) and belief similarity (p < .02); departure from linearity was not significant. Attitude similarity also had greater effects on other aspects of interpersonal evaluation than belief similarity. The results were discussed in terms of the locus of reinforcement of attitude similarity and of belief similarity.     

A neurophysiologic model for aggressive behavior in the cat

A neurophysiologic model for aggessive behavior in the cat is proposed. Stimulus-bound and seizure-bound aggression was evaluated in relation to limbic and basal ganglia induced seizures (after-discharges). Electrically induced limbic and basal ganglia afterdischarges were used because they are known to implicate septohypothalamic sites from which aggression can be elicited by direct stimulation. The occurrence of behavioral aggression is correlated with the discharge characteristics of a single discharging system and with two interacting discharging systems. Aggression is composed of autonomic and somato-motor components which poses relatively low and high thresholds, respectively, for their activation. Aggression occurring during a combined septum and amygdala discharge was more intense and prolonged than with a septum discharge alone. Participation of a slow frequency discharging basal ganglia system activated seizurebound aggression in an otherwise nonaggressive limbic seizure. The limbic and basal ganglia stimulations and after-discharges lowered the excitability threshold of the aggression system and made it more vulnerable to being activated by external stimuli, such as visual and auditory stimuli. These observations are reminiscent of patients with aggressive behavior associated with psychomotor seizures.     

Race vs belief as determinants of attraction,in a group interaction context

Three experiments which tested the’ effects of race vs belief similarity as determinants of prejudiced responding in a live interaction situation,are reported. Two black and two white confederates engaged a white S in a discussion of an issue (ROTC in Experiments I and II and abortion in III). One white and one black confederate agreed with the S’s position and the other pair disagreed. Ss then rated all four confederates on a variety of scales. Results showed strong belief effects in all three experiments but very few race effects. A few measures showed a “renegade effect” against dissimilar white confederates. It was concluded that simply increasing the power and realism of the experimental situation does not in any important way increase the number of racially prejudiced responses. Some conditions which may elicit strong and consistent race prejudice effects are discussed.     

Startbox-goalbox confinement durations as determinants of self-punitive behavior

Two levels of confinement duration (5 or 60 sec) in either startbox or goalbox were factorially combined with presence or absence of shock during extinction of a runway escape response in a self-punitive paradigm under a spaced-trials procedure. All groups were equated for amount and temporal spacing of handling before and after each trial. Shocked rats were more resistant to extinction than nonshocked rats only when startbox confinement was short. When startbox confinement was long, shock facilitated extinction. Long goalbox confinement enhanced running speed for shocked rats, but only in the presence of shock. It was suggested that duration of startbox confinement affects strength of conditioned fear, with long confinement leading to its extinction.     

Verbal imagery and connotation as memory-induced mediators of aggressive behavior.

Three studies investigated the effects of an information-processing variable (imagery-concreteness) on susceptibility to aggressive stimulation. Study 1 (n=83) results indicated that subjects' rating of imagery level and aggressive connotation for words can be manipulated independently. In study 2 (n=64), manipulations of verbal connotation and verbal imagery indicated that imagery level but not aggressive connotation significantly influenced the delayed recall of the verbal material. In Study 3 (n=60), males in a 2 X 2 between-subjects factorial design first learned lists of words varying in imagery (high or low) and verbal connotation (aggressive or neutral). Next, subjects were given the opportunity to shock their partners as part of a sham learning task. To induce arousal, all subjects learning high-imagery-aggressive word lists delivered significantly more intense shock to their partners. The results were interpreted as supporting an information-processing (memory) analysis of the effects of exposure to aggressive material.     

Exposure to ozone inhibits isolation-induced aggressive behavior of adult CD-1 male mice

Continuous exposure to ozone (O₃, 1.2 ppm) in adult CD-1 male mice for 20 consecutive days markedly influenced a number of items of aggressive behavior induced by 59 days of individual housing. The behavior of mice was videotaped on days 1, 3, and 5 of five consecutive daily encounters (10 min each; isolation days 55, 57, and 59). Ozone exposure caused an abatement of aggressive behavior and enhanced fear-associated displays shown by a significant decrease in the frequency of attacking and digging and an increase in freezing. Moreover, O₃ induced a decrease of time spent in attacking and exploration/activity. Nonexposed animals exhibited a day-dependent increase in self-grooming frequency which was not observed in O₃ mice; by contrast, freezing was higher in O₃ mice on day 5 of the test. Data suggest that O₃ exposure produces a remarkable reduction of mouse aggression, indirectly confirming previous findings on physical and neurobehavioral effects of O₃. © 1995 Wiley-Liss, Inc.     

A Markovian model of adult gaze behavior

This study was designed to test a proposed Markov chain model of adult gaze behaviors. Hypotheses for an individual's gaze behavior, dyadic visual interaction, and dyadic gaze states within an independent decision model were examined. Subjects were assigned to a same-or mixed-sex dyad and instructed to converse for approximately 5 min about life at the university. Video tapes of the conversations were unobtrusively obtained and scored by an observer of gaze behaviors for 4^1/2 min in 24 pairs of subjects: eight male, eight female, and eight mixed-sex dyads. The results indicate that the occurrence of a gaze behavior is dependent on a 0.6-sec history, but infrequently prolonged Looking behaviors were found to occur slightly more often than Markovian formulations predicted. The mathematical properties of gaze behavior demonstrated in this experiment are congruent with those of dialogic time patterns, suggesting a regularity in the gross temporal organization of nonverbal communications.