Preload and isometric force variability

Two experiments are reported, which examined the relative contributions of preload (resting force level), change of force, and the time taken to achieve the force in determining isometric force variability. The findings showed that change of force is the strongest determiner of peak force variability but that preload and time to peak force have smaller though systematic effects. A formula that predicts peak force variability is proposed, with preload as an additive effect to the ratio between the change of force level and the square root of time to peak force. These findings confirm that these three impulse variables are significant in predicting force variability and that the impact of rate of force on peak force variability is nonlinear.     

Temporal learning in 4 1/2- and 6-year-old children: role of instructions and prior knowledge

The present study investigates effects of different types of instructions (high-rate, interval, and minimal) during training with a fixed-interval schedule as a function of prior acquired temporal knowledge. A pretest was used to assess 4 1/2- and 6-year-old children's ability to understand the temporal parameters of a fixed-interval schedule of reinforcement. The results as a whole show that the control exerted by instructions given by the experimenter or elaborated by the subjects themselves on fixed-interval performance of young children depends on the interaction of two factors: development of verbal self-control skills and mastery of knowledge required by the rules forming the instructions.     

Interactions of preschool and kindergarten friends and acquaintances

The interactions of 4-, 5-, and 6-year-old friends and acquaintances in a peer teaching and game-playing situation were examined. The sample consisted of 102 children who were divided into pairs of same-age, same-sex friends or acquaintances using sociometrics. One child in each pair was randomly chosen to be the teacher and the other the learner. The teachers taught a novel board game to the learners. The most common teaching method was a combination of explaining and demonstrating the rules before the game began; older children gave more comprehensive instructions than younger children. At all ages, teachers were more likely than learners to take the first turn, issue commands, and change the rules. Friends were rated more involved with their partners, more emotionally expressive, and more competitive than acquaintances. Teachers who taught friends were rated more domineering than teachers who taught acquaintances, and learners who were taught by friends were rated more playful and friendly than learners taught by acquaintances.     

Victims' perceptions of social support: what is helpful from whom?

Although research has demonstrated that social interactions influence psychological well-being, little is known about what specific actions victims of stressful life events experience as helpful or unhelpful. Wortman and Dunkel-Schetter (1979) previously suggested that victims frequently experience rejection, withdrawal, and communication problems with those close to them. To address these issues, 55 cancer patients were interviewed concerning the specific actions they found to be helpful or unhelpful from several potential support providers: spouse, other family members, friends, acquaintances, others with cancer, physicians, and nurses. The data indicated that the Wortman and Dunkel-Schetter victimization model applied better to interactions with friends and acquaintances than to interactions with close family members. In addition, support was found to be partially dependent on the source: Particular actions were perceived to be helpful from some but not other network members. Implications for theory and research on social support are discussed.     

Continuity and change: assortative marriage and the consistency of personality in adulthood

How is personality stability possible amid the myriad of social changes and transformations that characterize a human life? We argue that by choosing situations that are compatible with their dispositions and by affiliating with similar others, individuals may set in motion processes of social interchange that sustain their dispositions across time and circumstance. To test this proposition we examined mate selection, using data on married couples from two ongoing longitudinal studies at the Institute of Human Development, University of California, Berkeley. Consistent with other research, the results point to homogamy as a basic norm in marriage. More important, the results show that marriage to a similar other promotes consistency in the intraindividual organization of personality attributes across middle adulthood. We offer some speculations for a more relational approach to the problem of individual continuity and change.     

Functional and dysfunctional impulsivity: personality and cognitive correlates

The 3 studies reported here were designed to clarify the nature of the personality trait of impulsivity. Two types of impulsivity were distinguished. Dysfunctional impulsivity is the tendency to act with less forethought than most people of equal ability when this tendency is a source of difficulty; most previous work on impulsivity appears to have focused on this trait. Functional impulsivity, in contrast, is the tendency to act with relatively little forethought when such a style is optimal. The present work indicates that these two tendencies are not highly correlated and that they bear different relations both to other personality traits and to the manner in which certain basic cognitive processes are executed.     

Suspicion of ulterior motivation and the correspondence bias

Three studies examined the hypothesis that when perceivers learn of the existence of multiple, plausibly rival motives for an actor's behavior, they are less likely to fall prey to the correspondence bias than when they learn of the existence of situational factors that may have constrained the actor's behavior. In the first 2 studies, Ss who learned that an actor was instructed to behave as he did drew inferences that corresponded to his behavior. In contrast, Ss who were led to suspect that an actor's behavior may have been motivated by a desire to ingratiate (Study 1), or by a desire to avoid an unwanted job (Study 2), resisted the correspondence bias. The 3rd study demonstrated that these differences were not due to a general unwillingness on the part of suspicious perceivers to make dispositional inferences. The implications that these results have for understanding attribution theory are discussed.     

Interpersonal competition can cause individuating processes

Two experiments investigated whether competitors attend to and individuate opponents. Interdependence theories predict that people individuate others on whom their outcomes depend rather than stereotyping them; this has been tested for cooperative but not for competitive interdependence. Competition separates such phenomena as unit formation in cooperation from interdependence per se, posited to be the crucial variable. In two experiments, Ss expected to compete or not compete with a competent or incompetent fictitious subject. Ss commented into a tape recorder about the person's attributes, some inconsistent and some consistent with expectations. As predicted, competitors (a) increased attention to inconsistencies, (b) drew more dispositional inferences about inconsistencies, and (c) formed more varied impressions. The role of competition in undercutting expectancy-based impressions and intergroup vs. interpersonal competition are discussed.     

The trait anxiety-perception score: a composite predictor for state anxiety

This article describes the development and initial evaluation of the A-Trait-Perception (ATP) score, a composite predictor for state anxiety. The ATP score is constructed from trait anxiety and situation perception data derived from the Endler Multidimensional Anxiety Scales (EMAS; Endler, Edwards, & Vitelli, 1989). ATP mathematically combines the individual's trait anxiety and situation perception profiles and adjusts these with a multiplier that reflects the individuals' sensitivity to particular types of situational elements in terms of state anxiety inducement. The utility of the resulting composite variable as a predictor of state anxiety was examined in the context of two field studies. Results of both studies indicated that the ATP variable offered a superior prediction of state anxiety, as compared to four individual trait anxiety facets (social evaluation, physical danger, ambiguous and daily routines). The theoretical import of these results is discussed.