‘Unwilling’ versus ‘unable’: capuchin monkeys’ (Cebus apella) understanding of human intentional action

A sensitivity to the intentions behind human action is a crucial developmental achievement in infants. Is this intention reading ability a unique and relatively recent product of human evolution and culture, or does this capacity instead have roots in our non‐human primate ancestors? Recent work by Call and colleagues (2004) lends credence to the latter hypothesis, providing evidence that chimpanzees are also sensitive to human intentions. Specifically, chimpanzees remained in a testing area longer and exhibited fewer frustration behaviors when an experimenter behaved as if he intended to give food but was unable to do so, than when the experimenter behaved as if he had no intention of giving food. The present research builds on and extends this paradigm, providing some of the first evidence of intention reading in a more distant primate relative, the capuchin monkey (Cebus apella). Like chimpanzees, capuchin monkeys distinguish between different goal‐directed acts, vacating an enclosure sooner when an experimenter acts unwilling to give food than when she acts unable to give food. Additionally, we found that this pattern is specific to animate action, and does not obtain when the same actions are performed by inanimate rods instead of human hands (for a similar logic, see Woodward, 1998 ). Taken together with the previous evidence, the present research suggests that our own intention reading is not a wholly unique aspect of the human species, but rather is shared broadly across the primate order.     

Comparing black-capped (Poecile atricapillus) and mountain chickadees (Poecile gambeli): use of geometric and featural information in a spatial orientation task

Since Cheng (Cognition 23:149–178, 1986) first proposed the “geometric module” in rats, a great deal of research has focused on how other species use geometric information and how geometric encoding may differ across species. Here, hand-reared and wild-caught black-capped chickadees and wild-caught mountain chickadees searched for food hidden in one corner in a rectangular environment. Previous research has shown that mountain chickadees do not spontaneously encode geometric information when a salient feature is present near the goal location. Using a slightly different training and testing procedure, we found that both hand-reared and wild-caught black-capped chickadees encoded geometric information, even in the presence of a salient landmark. Some, but not all, mountain chickadees also encoded geometric information. Overall, our results suggest that use of geometric information may be a less preferred strategy for mountain chickadees than for either wild-caught or hand-reared black-capped chickadees. To our knowledge, this is the first direct interspecies comparison of use of geometric information in a spatial orientation task.     

Building an active citizenry: the role of neighborhood problems, readiness, and capacity for change

Community-building initiatives strive to involve residents as the drivers of the change process, involving them in an array of activities including collective action efforts. Recent evaluations of many of these initiatives, however, suggest that developing the levels of resident involvement needed in such efforts is challenging. This study examines the neighborhood conditions that are related to whether and how much residents become involved in individual activism and collective action efforts. A random-digit-dial phone survey of 460 residents in 7 distressed neighborhoods suggested that while demographic variables were relatively unimportant, resident perceptions of neighborhood readiness (i.e., hope for the future and collective efficacy) and capacity for change (i.e., social ties and neighborhood leadership), and the level of neighborhood problems were strongly related to whether and how much residents were involved in individual and collective action efforts. Moreover, different elements of these neighborhood conditions were more or less important depending on the type and level of resident involvement. For example, while perceptions of neighborhood problems was the strongest predictor of whether an individual became involved at all, perceived strength of neighborhood leadership was the strongest predictor of an individual's level of activity. The implications of these findings for practitioners and scientists are discussed.     

Developmental sources of implicit attitudes

Explanations for implicit and explicit attitude dissociation have largely focused on causes of explicit attitudes. By contrast, this article examines developmental experiences as potential sources of implicit (more than explicit) attitudes, using attitudes toward smoking and body weight, which have shown dissociation with self-reports. In Study 1, smokers' implicit and explicit attitudes toward smoking were uniquely predicted by their early and recent experiences with smoking, respectively. In Study 2, participants' childhood and current weight uniquely predicted implicit and explicit body weight attitudes, respectively. Furthermore, being raised primarily by a beloved, heavyweight mother predicted proheavy implicit (but not explicit) attitudes. In Study 3, people's reports of pleasant dreams in childhood (but not currently) predicted their implicit attitudes toward dreams. In concert, results provide support for theorizing that implicit and explicit attitudes may stem from different sources of information and are, therefore, conceptually distinct.     

On the heritability of inspection time and its covariance with IQ: a twin study

Using the classical twin design, this study investigates the influence of genetic factors on the large phenotypic variance in inspection time (IT), and whether the well established IT–IQ association can be explained by a common genetic factor. Three hundred ninety pairs of twins (184 monozygotic, MZ; 206 dizygotic, DZ) with a mean age of 16 years participated, and 49 pairs returned approximately 3 months later for retesting. As in many IT studies, the pi figure stimulus was used and IT was estimated from the cumulative normal ogive. IT ranged from 39.4 to 774.1 ms (159±110.1 ms) with faster ITs (by an average of 26.9 ms) found in the retest session from which a reliability of .69 was estimated. Full-scale IQ (FIQ) was assessed by the Multidimensional Aptitude Battery (MAB) and ranged from 79 to 145 (111±13). The phenotypic association between IT and FIQ was confirmed (−.35) and bivariate results showed that a common genetic factor accounted for 36% of the variance in IT and 32% of the variance in FIQ. The maximum likelihood estimate of the genetic correlation was −.63. When performance and verbal IQ (PIQ & VIQ) were analysed with IT, a stronger phenotypic and genetic relationship was found between PIQ and IT than with VIQ. A large part of the IT variance (64%) was accounted for by a unique environmental factor. Further genetic factors were needed to explain the remaining variance in IQ with a small component of unique environmental variance present. The separability of a shared genetic factor influencing IT and IQ from the total genetic variance in IQ suggests that IT affects a specific subcomponent of intelligence rather than a generalised efficiency.     

Sex differences in the nature,realism, and correlates of body image

The present study examined sex differences in the nature and realism of body-image satisfaction, and the extent to which sex and sex role ideology moderated the relationships of body image to other indices of self-esteem and well-being. Accordingly, scales assessing body cathexis, self-esteem, depression proneness, and sex role ideology, as well as a questionnaire assessing perceptions of weight and dieting activities, were completed by 135 college women and 129 college men. As expected, women indicated significantly greater dissatisfaction with their bodies than did men. Women were likely to perceive themselves as overweight or slightly overweight, regardless of their actual weight, and most wanted to lose weight. Men who were dissatisfied tended to perceive themselves as underweight and wanted to gain rather than to lose weight. For both sexes, less positive attitudes to ward one's body were related to lower levels of self-esteem, although the relationship was significantly stronger for women than for men. The relationship between body attitudes and self-esteem was of approximately equal magnitude among traditional vs feminist women. For both sexes, more negative attitudes towards one's body were related to greater proneness to depression. Implications for further research are discussed.     

The impact of defibrillator discharges on psychological functioning of implantable cardioverter defibrillator recipients

A lag exists with respect to our understanding of the psychological demands and rehabilitation needs of individuals who have undergone implantable cardioverter defibrillator (ICD) implantation. The ICD is designed to transmit an electric shock to the heart to treat a potentially life-threatening arrhythmia. This study specifically examined the impact of defibrillator discharges on the psychological functioning of ICD recipients. A questionnaire was self-administered to 33 individuals who have been living with the ICD for at least 6 months. Results revealed that levels of anger and depression were significantly higher in those subjects who reported a lower discharge rate, while sense of well-being was significantly higher in those subjects who reported a greater discharge rate. Possible explanations for our findings were proposed as well as implications for clinical intervention were discussed.