Manual dexterity in the gorilla: bimanual and digit role differentiation in a natural task

The manipulative actions of mountain gorillas Gorilla g. beringei were examined in the context of foraging on hard-to-process plant foods in the field, in particular those used in tackling thistle Carduus nyassanus. A repertoire of 72 functionally distinct manipulative actions was recorded. Many of these actions were used in several variants of grip, finger(s) and movement path, both by different individuals and by the same individual at different times. The repertoire appears somewhat greater than that observed in comparable studies of monkeys, but a far more striking difference is found in the use of differentiated actions in concert. Mountain gorillas routinely and frequently deal with problems that involve: (1) bimanual role differentiation, with the two hands taking different roles but synchronized in time and space, and (2) digit role differentiation, with independent control of parts of the same hand used for separate purposes at the same time. The independent control that allows these abilities, so crucial to human manual constructional ability, is apparently general in African great apes. Role differentiation, between and within the hand, is evidently a primitive characteristic in the human arsenal of skills. Accepted after revision: 6 April 2001 Electronic Publication     

Salesperson characteristics affecting consumer complaint responses

The important relationship between consumer complaint behaviour and brand and store loyalty is well established. The range of factors that favourably influence the outcomes of complaining have received relatively less research attention. Therefore, this study tests the effects of two salesperson source characteristics: willingness to listen and product/store knowledge, on consumer complaint‐related perceptions and intentions in a retail setting. Mall shoppers participated in a consumer complaint experiment to test the hypothesised effects. The results indicate that both characteristics affect customer complaint responses, as well as consumer perceptions of the salesperson and the retail store. The findings of the study demonstrate that salesperson characteristics are important influences on positive or negative consumer complaint responses. Copyright © 2001 Henry Stewart Publications.     

THE EFFECTS OF FORM TRAINING ON FOUL‐SHOOTING PERFORMANCE IN MEMBERS OF A WOMEN'S COLLEGE BASKETBALL TEAM

The effects of instruction and feedback in proper form on foul‐shooting performance was evaluated in 3 players of a women's NCAA Division II college basketball team. Players showed an increase in percentage of shots made and in correct form compared to baseline shooting without instruction or feedback. All players reached criterion within seven training sessions. The results suggest that training proper form is an effective strategy for improving foul‐shooting performance.     

Evidence of Impaired Glucose Tolerance and Insulin Resistance in Patients With Alzheimer’s Disease

Alzheimer’s disease (AD) and diabetes rarely occur together, a finding that provides a possible clue as to the development of AD. Abnormal glucose metabolism is not limited to diabetes, but also can include impaired glucose tolerance, insulin resistance, and hyperinsulinemia. AD patients have significantly varying insulin levels after drinking sugared sodas and thus may be classified as insulin resistant. After reviewing the literature on impaired glucose tolerance and insulin production in AD, we present several hypotheses as possible explanations for the relationship between insulin resistance and AD. Finally, we suggest future studies, including studies on use of thiazolidinediones (currently used in the treatment of diabetes) in AD.     

Interviewing Witnesses: Forced Confabulation and Confirmatory Feedback Increase False Memories

In two experiments, adults who witnessed a videotaped event subsequently engaged in face-to-face interviews during which they were forced to confabulate information about the events they had seen. The interviewer selectively reinforced some of the participants' confabulated responses by providing confirmatory feedback (e.g., "Yes, _is the correct answer") and provided neutral (uninformative) feedback for the remaining confabulated responses (e.g., "O.K. _"). One week later, participants developed false memories for the events they had earlier confabulated knowingly. However, confirmatory feedback increased false memory for forcibly confabulated events, increased confidence in those false memories, and increased the likelihood that participants would freely report the confabulated events 1 to 2 months later. The results illustrate the powerful role of social-motivational factors in promoting the development of false memories.     

The Psychology of Nice People

Popular culture often describes being nice as a social disadvantage. However, research repeatedly finds that being agreeable is associated with a number of advantages. Literature noting the positive benefits of being agreeable is reviewed. The paper also addresses how agreeableness, one of the Big Five personality dimensions, is linked with higher-quality friendships, successful parenting, better academic and career performance, and health. The case is made that being agreeable is not equated to being easily influenced nor is it an artifact because of social desirability. Finally, cultural and gender differences related to agreeableness are addressed. Based on the review of the literature, it is postulated that being agreeable may be the path to enduring interpersonal relationships, happiness, success, and well-being.     

Effects of early institutionalization on the development of emotion processing: a case for relative sparing?

We tested the capacity to perceive visual expressions of emotion, and to use those expressions as guides to social decisions, in three groups of 8‐ to 10‐year‐old Romanian children: children abandoned to institutions then randomly assigned to remain in ‘care as usual’ (institutional care); children abandoned to institutions then randomly assigned to a foster care intervention; and community children who had never been institutionalized. Experiment 1 examined children's recognition of happy, sad, fearful, and angry facial expressions that varied in intensity. Children assigned to institutional care had higher thresholds for identifying happy expressions than foster care or community children, but did not differ in their thresholds for identifying the other facial expressions. Moreover, the error rates of the three groups of children were the same for all of the facial expressions. Experiment 2 examined children's ability to use facial expressions of emotion to guide social decisions about whom to befriend and whom to help. Children assigned to institutional care were less accurate than foster care or community children at deciding whom to befriend; however, the groups did not differ in their ability to decide whom to help. Overall, although there were group differences in some abilities, all three groups of children performed well across tasks. The results are discussed in the context of theoretical accounts of the development of emotion processing.