‘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.     

Displacing Danger: Managing Crime Through Deportation

This paper traces the development of the introduction of Bill C-44, the “danger to the public” clause that amended the Immigration Act of Canada in 1995, and considers the effects of the amendment to Canadian deportation policy on Jamaican nationals living in Canada. Starting with an examination of the increase in criminal deportation to Jamaica from Canada, the paper draws attention to the overall increases in total deportations to Jamaica from other countries including the USA and the UK between 1990 and 2004. Official crime statistics, and interviews with deported individuals and other Jamaican stakeholders are used to highlight the negative effects of deportation on deported persons and on the Jamaican society. The paper concludes with a discussion of deportation as a form of punishment and considers the implications of current deportation practices on global conceptions of security.     

Comprehension skill, inference-making ability, and their relation to knowledge

In this study we investigated the relation between young children's comprehension skill and inference-making ability using a procedure that controlled individual differences in general knowledge (Barnes & Dennis, 1998; Barnes, Dennis, & Haefele-Kalvaitis, 1996). A multiepisode story was read to the children, and their ability to make two types of inference was assessed: coherence inferences, which were essential for adequate comprehension of the text, and elaborative inferences, which enhanced the text representation but which were not crucial to understanding. There was a strong relation between comprehension skill and inference-making ability even when knowledge was equally available to all participants. Subsidiary analyses of the source of inference failures revealed different underlying sources of difficulty for good and poor comprehenders.     

A low-cost method for digitizing videotaped continuous movements on the Macintosh

We describe an inexpensive means of digitizing videotaped positions of moving points, such as the positions of the joints of a person who is performing an action. Single-frame video images and a Macintosh computer monitor are optically superimposed, using a half-silvered mirror, and the positions of reference points in the video image are manually clicked in by the operator, so that the screen coordinates of the reference points on each frame can be stored in a text file for later analysis. The digitizing program records comments and identifying information along with the position data.     

Knowing the meaning, getting the point, bridging the gap, and carrying the message: aspects of discourse following closed head injury in childhood and adolescence

Pragmatic communication or discourse was studied in 33 children and adolescents following closed head injury. Three-quarters of the sample was impaired on at least one of four discourse tests (knowing the alternate meanings of ambiguous words in context; getting the point of figurative or metaphoric expressions; bridging the inferential gaps between events in stereotyped social situations; and producing speech acts that express the apparent intentions of others). Resolution of ambiguity was correlated with word fluency and verbal domain knowledge, but not with object naming; understanding of metaphor was correlated with verbal domain knowledge, but not with literal sentence comprehension or with the formation of analogies; making inferences was correlated with working memory capacity but not with social knowledge; and producing speech acts was not correlated either with sentence construction or with social knowledge. These associations and dissociations reveal some of the correlates of impaired discourse processing after closed head injury in childhood and adolescence, as well as bearing on theoretical questions concerning the nature of normally developing discourse processes.