An individualized regression and clustering assessment of the social values of adults and children

Research investigating social values in interdependency situations has generally demonstrated age differences across the 5- to 10-year-old age range. However, the precise nature of these differences is unclear. Further, the differences in the social values of adults and children has not been addressed. The present study examined the social values of undergraduates and children using a measurement technique designed to allow an accurate inference of social values. Ninety-one 6- to 10-year-old children and 100 undergraduates rated the desirability of a set of outcomes which systematically varied with regard to the benefits to themselves and another person. Theoretically specified characteristics of the outcomes were then used to generate a regression equation predicting the desirability ratings separately for each individual. These regression equations were then clustered into groups of individuals who used decision rules characteristic of the major social values. The results indicate that the 8- to 10-year-old children, compared to the 6- to 7-year olds, more often expressed a social value involving equality and tended to less often express a social value involving superiority. Comparison of the social values expressed by the children and adults indicated that the adults more often expressed group-enhancement and individualism social values and less often expressed a social value involving superiority.     

Stimulus selection in passive avoidance learning and retention: weanling, periadolescent, and young adult rats

Periadolescent rats exhibit a number of behavioral differences in comparison with younger or older animals. For instance, periadolescents tend to show enhanced acquisition of simple active avoidance tasks, but impaired acquisition of more complex appetitive and aversive discriminations. In this experiment, rats were trained on a simple passive avoidance task at one of three ages, as weanlings (25 days), periadolescents (35 days), or young adults (45 days). Training occurred in the presence of both a redundant discriminative stimulus and a specified, redundant contextual stimulus. The periadolescents did not differ from either younger or older rats in rate of learning the passive avoidance task. The retention performance of these animals was then tested following a change in either, neither, or both of the redundant cues. When a measure of performance that controls for baseline activity was used, it was observed that periadolescents were not disrupted by a change in the redundant discriminative stimulus, a cue change that clearly disrupted performance in 25- and 45-day-old animals, and tended to be more disrupted by the contextual change than younger or older rats. It is hypothesized that the alterations in performance exhibited by periadolescents may be related to an ontogenetic alteration in stimulus selection modulated by the catecholaminergic systems.     

Postsurgical enrichment aids adult hemidecorticate rats on a spatial navigation task

The effect of environmental enrichment on normal rats, rats that received hemidecortication at birth, and rats that received hemidecortication when adult was studied in the Morris water task, which is a spatial navigation task requiring the use of distal cues for successful performance. Enrichment was achieved by housing the rats for 90 days in a large outdoor compound that was designed to model a natural environment. Adult hemidecorticated lab-raised rats were severely impaired in the acquisition of the task but neonatally hemidecorticated rats, although also impaired, showed significant sparing. Postsurgical, but not presurgical, enrichment of adult hemidecorticated rats significantly enhanced their recovery. Enrichment had little effect on neonatally decorticated rats or on normal rats. Although there were no gross anatomical changes associated with enrichment, the paradigm provides both a robust phenomena and a cortically dependent task that is ideal for investigating the processes in the remaining intact hemisphere that must support recovery.     

Age norms for impulsiveness,venturesomeness and empathy in children

A total of 1505 children (633 boys and 872 girls) completed the I₆ Impulsiveness Questionnaire. Reliabilities, scale intercorrelations and means and standard deviations are given after slight modifications were made to the original scoring key on the basis of factor analyses. Age means for both sexes are also given.     

When celebrities talk,children listen: An experimental analysis of children's responses to TV ads with celebrity endorsement

Two studies tested the effects of TV ads with celebrity endorsement on the product preference and understanding of 8- to 14-year-old boys. Study 1 compared two ads for a model racer. One had celebrity endorsement (by a famous race driver) and footage of real automobile racing featuring the celebrity (live action); the second had neither feature. Study 2 employed one ad for a different brand of model racer edited to generate a 2 (endorser presence) by 2 (inclusion of live racetrack action) factorial design. A total of 415 boys were exposed to one of the experimental ads or a control ad, embedded in a new animated children's adventure program. Preference for the advertised brand of model racer (pre- and postviewing) and a number of cognitive variables were assessed. Exposure to endorsement led to increased preference for the toy and belief that the celebrity was expert about the toy. Live action led to exaggerated estimates of the physical properties of the toy and the belief that the ad was not staged. The 8- to 10-year-olds associated the glamour of the endorser with the toy and were more reliant on his advice than were 11- to 14-year-olds. However, the two age groups were not differentially affected by the ads. Contrary to the speculation of many researchers, understanding about advertising intent and techniques and cynicism about ads had almost no influence on product preference after viewing.     

Effects of perceptual and conceptual similarity in semantic priming

Summary The study investigates the different contributions to semantic priming of two components of the semantic representation underlying a word. The two components are perceptually based information and conceptually based information. Perceptual information is based on physical attributes such as shape or color, while conceptual information consists of more abstract elements such as functional attributes. The question asked in this study was whether both components would produce an effect in semantic priming. Pairs of words either related because of a conceptual property (banana-apple), a perceptual property (ball-apple), or both because of a perceptual and conceptual property (cherry-apple) were presented as prime and target in a lexical decision and a word-naming task. The results showed independent contributions of perceptual and conceptual attributes to semantic priming.This research was supported by a grant from the Dutch Organization for the Advancement of Pure Research (ZWO). All three authors are senior authors and have contributed to all parts of the project.     

Representation of linear orders

Two binary classification tasks were used to explore the associative structure of linear orders. In Experiment 1, college students classified English letters as targets or nontargets, the targets being consecutive letters of the alphabet. The time to reject nontargets was a decreasing function of the distance from the target set, suggesting response interference mediated by automatic associations from the target to the nontarget letters. The way in which this interference effect depended on the placement of the boundaries between the target and nontarget sets revealed the relative strengths of individual interletter associations. In Experiment 2, students were assigned novel linear orders composed of letterlike symbols and asked to classify pairs of symbols as being adjacent or nonadjacent in the assigned sequence. Reaction time was found to be a joint function of the distance between any pair of symbols and the relative positions of those symbols within the sequence. The effects of both distance and position decreased systematically over 6 days of practice with a particular order, beginning at a level typical of unfamiliar orders and converging on a level characteristic of familiar orders such as letters and digits. These results provide an empirical unification of two previously disparate sets of findings in the literature on linear orders, those concerning familiar and unfamiliar orders, and the systematic transition between the two patterns of results suggests the gradual integration of a new associative structure.     

Detection versus discrimination of visual orientation

The role of focused attention in vision is examined. Recent theories of attention hypothesize that serial search by focal attention is required for discrimination between different combinations of features. Experiments are reported which show that the mixture of a few (less than five) horizontal and vertical line segments embedded in an aggregate of diagonal line segments can be rapidly counted (also called 'subitizing') by a parallel (preattentive) process, while the discrimination between horizontal and vertical orientation requires serial search by shifting focal attention to each line segment. Thus detecting and counting targets that differ in orientation can be done in parallel by a preattentive process, whereas knowing 'what' the orientation of a target is (horizontal or vertical, ie of a single conspicuous feature) requires a serial search by focal attention.