Evolution of kin recognition mechanisms in a fish

Animal Cognition - Both selection and phylogenetic history can influence the evolution of phenotypic traits. Here we used recently characterized variation in kin recognition mechanisms among six...     

Filtering and condensation tasks with integral and separable dimensions

Speed of classification was measured with a filtering task (only one dimension relevant) and a condensation task (two dimensions relevant) with integral dimensions of Munsell value and chroma and separable dimensions of value and size. The filtering task was easier with separable than with integral dimensions, but the condensation task was easier with integral than with separable dimensions. The results emphasize the importance of dimensional structure with separable dimensions and similarity or distance structure with integral dimensions.     

Interaction of stimulus dimensions in concept and choice processes

Four major types of interaction of stimulus dimensions based on perceptual research are described: integral, configural, separable, and asymmetric separable. Implications of these interactions for concept and choice processes are discussed. With regard to concept learning, it is argued that integral or configural interactions are desirable within the set of relevant and within the set of irrelevant dimensions used to generate stimuli, but that relevant dimensions should be separable from irrelevant dimensions. With regard to choice processes, integral or configural dimensions produce choices based on ordinary distance relations or equivalent parallel processing of dimensions. With separable dimensions, however, serial processing is at least possible; and such processing can lead to choices in which the subset of stimuli and the order of processing of dimensions affects the choice outcomes.     

The effect of redundant stimulus elements on visual discrimination as a function of element heterogeneity,equal discriminability,and position uncertainty

Garner and Lee (1962) showed no gain in visual discrimination accuracy with addition of redundant stimulus elements. Eriksen and Lappin (1965) showed a substantial gain. One experiment reported here indicates that the discrepancy is not due to the fact that the earlier experiment used heterogeneous stimulus elements. A second experiment indicated that the gain in discrimination accuracy does occur when the additional stimulus elements have the same discriminability as the original elements. It also showed that position uncertainty itself has no effect on the gain with redundant elements, but is a convenient procedural device for maintaining fixation and thus equal element discriminability. Three models of perceptual independence fit the data.     

The effect of stimulus element redundancy on speed of discrimination as a function of state and process limitation

The effect of spatially repeated stimulus elements on the speed of discrimination, measured in a sorting task, was determined under conditions of low stimulus visibility (state limitation) and high stimulus similarity (process limitation). A significant increase in speed of sorting stimuli was found when the stimuli were state limited but not when process limited, even though base speeds were the same in both cases. It is concluded that element redundancy will improve discrimination performance only when the need for the improvement is a state limitation.     

Abolishing Morality

Moral anti-realism comes in two forms – noncognitivism and the error theory. The noncognitivist says that when we make moral judgments we aren’t even trying to state moral facts. The error theorist says that when we make moral judgments we are making statements about what is objectively good, bad, right, or wrong but, since there are no moral facts, our moral judgments are uniformly false. This development of moral anti-realism was first seriously defended by John Mackie. In this paper I explore a dispute among moral error theorists about how to deal with false moral judgments. The advice of the moral abolitionist is to stop making moral judgments, but the contrary advice of the moral fictionalist is to retain moral language and moral thinking. After clarifying the choice that arises for the moral error theorist, I argue that moral abolitionism has much to recommend it. I discuss Mackie’s defense of moral fictionalism as well as a recent version of the same position offered by Daniel Nolan, Greg Restall, and Caroline West. Then I second some remarks Ian Hinckfuss made in his defense of moral abolitionism and his criticism of “the moral society.” One of the worst things about moral fictionalism is that it undermines our epistemology by promoting a culture of deception. To deal with this problem Richard Joyce offers a “non-assertive” version of moral fictionalism as perhaps the last option for an error theorist who hopes to avoid moral abolitionism. I discuss some of the problems facing that form of moral fictionalism, offer some further reasons for adopting moral abolitionism in our personal lives, and conclude with reasons for thinking that abolishing morality may be an essential step in achieving the goals well-meaning moralists and moral fictionalists have always cherished.

Parents’ Verbal Communication and Childhood Anxiety: A Systematic Review

Parents’ verbal communication to their child, particularly the expression of fear-relevant information (e.g., attributions of threat to the environment), is considered to play a key role in children’s fears and anxiety. This review considers the extent to which parental verbal communication is associated with child anxiety by examining research that has employed objective observational methods. Using a systematic search strategy, we identified 15 studies that addressed this question. These studies provided some evidence that particular fear-relevant features of parental verbal communication are associated with child anxiety under certain conditions. However, the scope for drawing reliable, general conclusions was limited by extensive methodological variation between studies, particularly in terms of the features of parental verbal communication examined and the context in which communication took place, how child anxiety was measured, and inconsistent consideration of factors that may moderate the verbal communication–child anxiety relationship. We discuss ways in which future research can contribute to this developing evidence base and reduce further methodological inconsistency so as to inform interventions for children with anxiety problems.