The empirical case for role-governed categories

Most theories of categorization posit feature-based representations. Markman and Stilwell (2001) argued that many natural categories name roles in relational systems and therefore they are role-governed categories. There is little extant empirical evidence to support the existence of role-governed categories. Three experiments examine predictions for ways that role-governed categories should differ from feature-based categories. Experiment 1 shows that our knowledge of role-governed categories, in contrast to feature-based categories, is largely about properties extrinsic to category members. Experiment 2 shows that role-governed categories have more prominent ideals than feature-based categories. Experiment 3 demonstrates that novel role-governed categories are licensed by the instantiation of novel relational structures. We then discuss broader implications for the study of categories and concepts.     

Do wild New Caledonian crows (<Emphasis Type="Italic">Corvus moneduloides</Emphasis>) attend to the functional properties of their tools?

New Caledonian crows are the most proficient non-hominin tool manufacturers but the cognition behind their remarkable skills remains largely unknown. Here we investigate if they attend to the functional properties of the tools that they routinely use in the wild. Pandanus tools have natural barbs along one edge that enable them to function as hooking implements when the barbs face backwards from the working tip. In experiment 1 we presented eight crows with either a non-functional (‘upside-down’) or a functional pandanus tool in a baited hole. Four of the crows never flipped the tools. The behaviour of the four flipping birds suggested that they had a strategy of flipping a tool when it was not working. Observations of two of the eight crows picking up pandanus tools at feeding tables in the wild supported the lack of attention to barb direction. In experiment 2 we gave six of the eight crows a choice of either a barbed or a barbless pandanus tool. Five of the crows chose tools at random, which further supported the findings in experiment 1 that the crows paid little or no attention to the barbs. In contrast, a third experiment found that seven out of eight crows flipped non-functional stick tools significantly more than functional ones. Our findings indicate that the crows do not consistently attend to the presence or orientation of barbs on pandanus tools. Successful pandanus tool use in the wild seems to rely on behavioural strategies formed through associative learning, including procedural knowledge about the sequence of operations required to make a successful pandanus tool. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Learning from experience: Examining the impact of client work upon two trainee therapists

This qualitative research study, focusing on the learning and change of two trainee therapists over a nine‐month period, was conducted by the trainees themselves. In collecting and analysing their data, the researchers made use of the heuristic methodology, to which some of the principles of the co‐operative inquiry methodology were added. The findings shed light on some of the ways in which trainee counsellors and psychotherapists might learn through their work with clients, the forms and contexts in which this learning may arise, and how the learning might affect the trainees. The findings additionally highlight some of the possible benefits of engaging in research for trainee counsellors and psychotherapists, in terms of their roles as practitioners. These include positive changes in the ways in which they work with clients, and changes in the ways they think about their practice.     

Expectancy Disconfirmation and Negotiator Reactions Across Negotiation Episodes

In the negotiation literature, relatively little attention has been paid to the impact of negotiator goals and expectancy disconfirmations on negotiator behaviors and affective outcomes. We found that negotiators with larger negative expectancy disconfirmations were less satisfied; set lower targets for a subsequent negotiation; and were more likely to settle with the other party in the second negotiation, rather than requiring third-party imposition of a settlement. Those negotiators who settled had more positive feelings and perceptions about the negotiation and set higher targets for a third negotiation. Further, negotiators who experienced repeated high levels of negative expectancy disconfirmation also experienced the greatest decrements in their feelings and perceptions across negotiation episodes. Implications of study findings for future research are discussed.     

Considerations Relating to the Study of Group Differences in Intelligence

ABSTRACT— There are signs that the debate over racial and gender differences in intelligence is about to begin again. In this article we will be concerned primarily with racial differences but will make remarks about gender differences where applicable. Previously there have been bitter arguments over whether or not races exist, over whether it is either important or proper to study racial and gender differences in intelligence, and over the conclusions that have been drawn about environmental and genetic causes as determinants of these differences. We argue that races do, indeed, exist and that studying differences in cognitive competence between groups is a reasonable thing to do. We also point out that past research on both racial and gender differences in intelligence has been marked by methodological errors and overgeneralizations by researchers on all sides of the issue. We propose ten principles of design, analysis, and reporting that ought to be considered carefully when doing or evaluating research in this area.     

Evil and theistic minimalism

International Journal for Philosophy of Religion -     

Statistical learning in a serial reaction time task: access to separable statistical cues by individual learners.

The ability of adult learners to exploit the joint and conditional probabilities in a serial reaction time task containing both deterministic and probabilistic information was investigated. Learners used the statistical information embedded in a continuous input stream to improve their performance for certain transitions by simultaneously exploiting differences in the predictability of 2 or more underlying statistics. Analysis of individual learners revealed that although most acquired the underlying statistical structure veridically, others used an alternate strategy that was partially predictive of the sequences. The findings show that learners possess a robust learning device well suited to exploiting the relative predictability of more than I source of statistical information at the same time. This work expands on previous studies of statistical learning, as well as studies of artificial grammar learning and implicit sequence learning.     

Affective valence and memory in depression: dissociation of recall and fragment completion.

Depressed (n = 16) and nondepressed (n = 16) subjects' memory for affectively valenced words was assessed by an explicit test (free recall) and an implicit test (word fragment completion). Under free-recall instructions, depressed subjects recalled significantly more negatively valenced than positively valenced words, whereas the opposite pattern was observed in nondepressed control subjects. These results replicate those previously reported in the literature. The differential effect of word valence was absent, however, when memory was tested implicitly: Depressed and nondepressed subjects exhibited equivalent priming of positive and negative words. These data are discussed in terms of Williams, Watts, MacLeod, and Mathews's (1988) model of depression.