‘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.     

Conspicuous donation behaviour: scale development and validation

• This paper builds on the concept of conspicuous donation behaviour (CDB) through further conceptualisation and operationalisation of this construct. The paper reports on developing the CDB scale via a three‐stage process, which includes five data collections using a total of 1311 respondents. The data analysis indicates that the resulting eight‐item (two factor) CDB scale has face, content, convergent, discriminant and predictive validity and the CDB scale is reliable across samples. The CDB scale has the potential for significant usage in the development and testing of theory, as well as in practical applications.

Copyright © 2009 John Wiley & Sons, Ltd.     

Developmental changes in neural activity to familiar words and gestures

Infants younger than 20 months of age interpret both words and symbolic gestures as object names. Later in development words and gestures take on divergent communicative functions. Here, we examined patterns of brain activity to words and gestures in typically developing infants at 18 and 26 months of age. Event-related potentials (ERPs) were recorded during a match/mismatch task. At 18 months, an N400 mismatch effect was observed for pictures preceded by both words and gestures. At 26 months the N400 effect was limited to words. The results provide the first neurobiological evidence showing developmental changes in semantic processing of gestures.     

Abuse History, World Assumptions, and Religious Problem Solving

At a Christian university, 167 subjects completed questionnaires measuring worldview assumptions, religious problem solving, physical and emotional abuse, and subjects' beliefs about whether they had been "abused." Results indicated that worldview assumptions were not related to actual abuse histories. Instead, such assumptions were related to the subjects' beliefs that they had been abused. Subjects who believed that they had been abused had more negative views of the impersonal world, people, and themselves; they were also more likely to see events as random. Both actual abuse history and subjects' beliefs that they had been abused were related to religious problem-solving styles. Finally, problem-solving styles were related to various worldview assumptions. Results are discussed in terms of previous research on abuse and in the psychology of religion.