Impulse characteristics in rapid movement: implications for impulse-variability models

Three untested assumptions of the impulse-variability model were examined in two experiments utilizing rapid, uni-planar limb movements. Experiment 1 varied movement distance (A) and movement time (MT) in a rapid-timing paradigm where the subject moved a lever through a certain distance in a certain time. Experiment 2 varied A in a reversal response where the S made a rapid elbow flexion and extension in a given MT. Displacement recordings were made on every trial. KR (knowledge of results) about MT was given after every trial. The results can be summarized as follows: (a) As predicted by the model, variations in impulse size and velocity were directly related to the impulses size; (b) There was no correlation between the accelerative and decelerative impulse durations recorded during the reversal response supporting the notion that the impulses might be independent; (c) Negative correlations (-.20 to -.50) were demonstrated between peak acceleration and impulse duration for both experiments, counter to the predictions of the model; and (d) Counter to the predictions of the model, timing error (VEt) increased as A decreased for rapid-timing responses. When the correlational results are taken into account, the model has the capacity to account for curvilinear relationships between relative timing error and movement speed. Overall, the results suggest that the impulse variability model requires some restructuring before it can be considered a viable model for the control of rapid limb movements.     

An examination of rapid positioning movements with spatiotemporal constraints

Unidirectional positioning movements with spatiotemporal constraints were examined as a test of impulse-timing theory (Schmidt, 1976; 1980; Wallace, 1981). Movements were examined at the kinematic, kinetic, and neuromuscular levels in three experiments. In the first experiment, displacement was held constant while five different movement times were examined. Both amplitudes and durations of the EMG and the kinetic variables were related to movement time. The results generally support the impulse-timing model. In the second experiment, movements were performed to a target at each of four distances in a constant movement time. EMG and force amplitudes and, unexpectedly, accelerative-force duration were modulated to achieve changes in displacement when movement time was constant. In the third experiment, movement time and displacement were simultaneously varied resulting in four conditions with equal average velocities. The results of this experiment were not as clear and exhibited individual differences. EMG duration did not always vary with changes in movement time. The results of all three experiments could not be adequately accounted for by the impulse-timing model.     

Predictors of naturalistic sexual aggression

This research integrated within a theoretical and empirical framework varied predictor factors pertaining to males' sexual aggression against women. The selection of predictors was guided by theorizing that sexual aggression is caused by the interaction among multiple factors, including those creating the motivation for the act, those reducing internal and external inhibitions, and those providing the opportunity for the act to occur. The predictor factors assessed were sexual arousal in response to aggression, dominance as a motive for sexual acts, hostility toward women, attitudes accepting of violence against women, psychoticism, and sexual experience. A measure assessing self-reported sexual aggression (primarily among acquaintances) in naturalistic settings served as the dependent measure. The subjects were 155 males. As expected, nearly all the predictor factors significantly related to sexual aggression. In addition, much better prediction of such aggression was achieved by a combination of these factors than by any one individually. It was also found that including interactions among these predictors yielded a regression equation that was more successful in relating to sexual aggression than an equation using an additive combination only. The relevance of these data to the causes and prediction of violence against women is discussed.     

Sexual arousal in response to aggression: ideological, aggressive, and sexual correlates

In two experiments we assessed the impact of aggression on nonrapists' sexual arousal. In the first, both male subjects (n = 37) and female subjects (n = 43) reported more sexual arousal in response to nonaggressive than to aggressive depictions when the portrayals were sexually explicit, but the opposite occurred when the portrayals were nonsexual. Only male subjects (N = 359) participated in the second experiment. On the basis of their self-reported sexual arousal to the use of force, they were classified into the no arousal, moderate arousal or high arousal from force groups. To evaluate the veridicality of this classification, we assessed some subjects' (n = 118) penile tumescence in response to various depictions. The findings generally replicated those of the first experiment and confirmed the accuracy of the arousal-from-force classification. The no arousal and the moderate arousal from force subjects were less sexually aroused by aggressive than by nonaggressive portrayals, but the opposite was found for the high arousal from force group. Using the entire sample (N = 359), we also assessed differences on various factors among these three groups. We found strong differences on ideological factors, including acceptance of violence against and dominance over women. We also found differences in acceptance of nonsexual aggression and in subjects' beliefs that they might actually use force against women. In contrast, differences were not found on sexuality factors. The data's implications for theories on the causes of rape are discussed.     

Predicting adult temperament from minor physical anomalies

It is known that in children, individual differences in temperament are linked to rates of minor physical anomalies (MPAs). These anomalies are a standard set of 17 nonobvious but measurable characteristics of the face, hands, and feet. We explored the relation between MPAs and temperament in adults. An intact sample of 88 undergraduates completed a battery of personality tests and lifestyle questions, and then were examined for MPAs. The index of MPAs for each subject was simply the total count out of 17. The results showed a pattern of correlates parallel to that found in children. Among male subjects, correlations with MPAs were significant for the Physical Activity and Clumsiness factors of the lifestyle inventory as well as for measures of emotionality, extraversion, masculinity, femininity, and Type A personality. The MPA index was also predictive of a behavioral index of temperament in male subjects. No correlations were significant among female subjects.     

Peers' granting of control to women with different sex role identities: implications for depression

This investigation is one of a series of studies seeking to determine the degree of control given to women with different sex role identities. This study focused on the extent to which peers were willing to grant control to women with different sex role identities if working individually with each woman on various two-person tasks. The results indicated that women with different sex role identities were granted different amounts of control by their peers as a function of the type of two-person task under consideration. Women rated high on masculinity were granted greater control on enjoyable and creative tasks, whereas women rated low in masculinity were given more control on methodical and less enjoyable tasks. Women judged high in femininity were given control on tasks requiring interpersonal skills. These findings were discussed within the context of learned helplessness theory as a possible aid in understanding why more women than men become depressed.     

Altruism and aggression: the heritability of individual differences

Five questionnaires measuring altruistic and aggressive tendencies were completed by 573 adult twin pairs of both sexes from the University of London Institute of Psychiatry Volunteer Twin Register. The questionnaires measured altruism, empathy, nurturance, aggressiveness, and assertiveness. The intraclass correlations for the five scales, respectively, were .53, .54, .49, .40, and .52 for 296 monozygotic pairs, and .25, .20, .14, .04, and .20 for 179 same-sex dizygotic pairs, resulting in broad heritability estimates of 56%, 68%, 70%, 72%, and 64%. Additional analyses, using maximum-likelihood model-fitting, revealed approximately 50% of the variance on each scale to be associated with genetic effects, virtually 0% with the twins' common environment, and the remaining 50% with each twins' specific environment and/or error associated with the test. Correcting for the unreliability in the tests raised the maximum-likelihood heritabilities to approximately 60%. Age and sex differences were also found: altruism increased over the age span from 19 to 60, whereas aggressiveness decreased, and, at each age, women had higher scores than men on altruism and lower scores on aggressiveness.     

Deprivation in the early mother-daughter relationship: A factor in the development of the narcissistic personality

Depriving mother-child relationships at an early age lay the foundation for narcissistic disturbances. Here, the specific focus is on mother-daughter relationships and the lack of appropriate maternal recognition and admiration of the infant. The particular treatment modality combines individual psychotherapy with a female therapist and group therapy in an all-women's group. The transferential phenomena to the various women found in this treatment situation are instrumental in helping the female patient achieve a significant change in her narcissistic personality.     

Macrocosm to microcosm: Toward a systemic model of personality

This paper attempts to: (1) provide a paradigm through which to understand the human self and, (2) bring some order out of the variety of theories of personality and strategies of change used in clinical practice today. Drawing on modern physics and general systems theory, a multi-leveled, systemic model incorporating physical, psychological, and spiritual dimensions is proposed and then applied to a representative clinical case. Implications of this model for clinical work and for a spiritual understanding of personality are elaborated.