Changes in limb stiffness under conditions of mental stress

In 2 experiments, the effects of mental stress on limb stiffness were investigated. The relative contribution to arm stiffness of individual muscle activity, co-contraction, muscle reflexes, and postural adjustments were examined. In each experiment, participants (N = 24, Experiment 1; N = 16, Experiment 2) held their supinated hand under a tray that they were required to return to horizontal after it had been suddenly released. Electromyographic activity in the biceps and triceps muscles was recorded, as were elbow and wrist angles and tray displacement. In Experiment 1, mental arithmetic stress was shown to lead to decreased tray displacement (i.e., increased resistance) compared with displacements under the control, unstressed condition, as well as to increased elbow flexion before tray release. In Experiment 2, the increased resistance to perturbation caused by mental stress was found to be independent of initial elbow angle, but to vary as a function of the amount of upward force exerted before tray release. The authors conclude that stress-induced increases in limb stiffness result from changes in the initial position of the elbow, specified by its angle, together with the initial force exerted by participants to counteract the mechanical perturbations.     

Industrial buyers' perception of effective selling'

The most fundamental aspect of commerce is interaction between buyers and sellers. Accordingly, the psychological study of selling techniques can be considered as old as trade. This study investigated two categories of selling techniques composed of 17 objection-addressing and 13 sale-dosing strategies. Reported are survey responses from 242 industrial buyers, frequent targets of selling techniques, who were asked to identify which technique from each category they associated with salespersons' effective selling behavior.     

Property and prejudice: How racial attitudes and social‐evaluative concerns shape property appraisals

Property evaluations rarely occur in the absence of social context. However, no research has investigated how intergroup processes related to prejudice extend to concepts of property. In the present research, we propose that factors such as group status, prejudice and pressure to mask prejudiced attitudes affect how people value the property of racial ingroup and outgroup members. In Study 1, White American and Asian American participants were asked to appraise a hand‐painted mug that was ostensibly created by either a White or an Asian person. Asian participants demonstrated an ingroup bias. White participants showed an outgroup bias, but this effect was qualified. Specifically, among White participants, higher racism towards Asian Americans predicted higher valuations of mugs created by Asian people. Study 2 revealed that White Americans' prejudice towards Asian Americans predicted higher valuations of the mug created by an Asian person only when participants were highly concerned about conveying a non‐prejudiced personal image. Our results suggest that, ironically, prejudiced majority group members evaluate the property of minority group members whom they dislike more favourably. The current findings provide a foundation for melding intergroup relations research with research on property and ownership.     

Play fighting between kindling-prone (FAST) and kindling-resistant (SLOW) rats

Differences in the play behavior of 2 strains of rats suggest that different components of play fighting can be modified independently. The development of play fighting in cross-strain pairs of familiar and unfamiliar rats was examined to determine whether interacting with a non-congruent pair-mate would alter the pattern of play typical for each strain. In both strains, changes in play fighting were observed throughout development, but partner identity appeared to influence play fighting in different ways depending on age. These data suggest that some components of play may be more impervious to changes in social environment than other components.     

Transfer of Work Decrement in Motor Learning

Two experiments tested the hypothesis that the decremental effects of massed practice are due to the development of a negative drive (Hull’s I_r). The results indicated that the decremental effects of massed practice on either the pursuit rotor or the two-hand coordinator do not transfer to depress performance or reminiscence on the other task. The results did not support Hull’s drive interpretation but were explained by theories attributing decrement to a decreased level of arousal.     

Structural studies of ultrathin zirconia dielectrics

We present detailed structural and chemical studies on ultrathin zirconia films grown by ultraviolet oxidation and natural (no ultraviolet light) oxidation of Zr precursor metal layers on SiO2-passivated Si(100) wafers. Quantitative electron-energy-loss spectroscopy (EELS) was used to obtain the chemical composition and electronic structure on an atomic scale. The EELS OK near-edge fine structure was used as a fingerprint to study the stoichiometry and composition variation in the dielectric stacks. X-ray absorption spectroscopy studies were performed in order to aid interpretation of the EELS results. The electronic structure data are correlated with the electrical performance of the films.     

Anxiety and affiliation in children

Hypotheses about the relationship between anxiety and affiliation derived from the psychoanalytic, drive, and social comparison models were tested by exposing high anxious (HA) and low anxious (LA)Ss to stress and subsequently to conditions meant to fulfill either nurturance or information needs. Unstressed and non-need fulfilled control groups were included. (N=224 grade school children.) Stress significantly increased the strength of adult affiliating in HA Ss; nurturance reduced it. Peer affiliating was not influenced by stress or information, nor did the conditions affect the affiliation of LASs. Results supported the hypothesis that dependency motives mediate the anxiety-affiliation relationship.This study is based on a doctoral dissertation completed at Yale University. The author thanks Prof. Seymour Sarason, who directed the thesis, and the children, teachers, and school psychologists of Milford, Conn. whose cooperation made this study possible.     

Social Determinants of HIV Among Men Who Have Sex with Men in Cape Town

Little is known about how social factors influence vulnerability to, and consequences of, HIV infection among men who have sex with men (MSM) in South Africa. This study aimed to analyse social stratification and its links with HIV among MSM in Cape Town, South Africa. Six interviews and six focus group discussions (n = 25) were conducted. Tools were based on the World Health Organisation’s Commission on the Social Determinants of Health framework. Directed content analysis was used to analyse data. Race and education were directly linked to social position. MSM from lower social positions were more vulnerable to HIV, and had more negative consequences of HIV infection, compared to wealthier MSM. Engagement with community leaders, health workers and police to promote inclusion could reduce vulnerability of MSM to HIV. Increased access to free, non-discriminatory HIV-related services would reduce inequities in access to HIV services by MSM.     

The influence of acceptance goals on self‐presentational efforts

The current work examined whether self‐presentational efforts are influenced differently when people hold a goal to establish, maintain or repair an interpersonal connection. Results supported the counterintuitive prediction that participants with a repair goal would convey a less favourably oriented persona (e.g. less friendly, less similar and less genuine) compared to those with an establish or maintain goal. The efforts of repair goal participants were also perceived as less effective. The analysis also showed that certain self‐presentation dimensions (i.e. friendliness, genuineness and similarity) mediated the relationship between acceptance goals and perceived effectiveness. The findings extend and contribute to the self‐presentation and belongingness literatures.