Pathological left-handedness and familial sinistrality in relation to degree of mental retardation

The relationship between personal and familial hand preference and mental retardation was examined. Six unimanual tasks were performed by 232 subjects within four mental retardation severity groups. Family handedness histories were obtained. Right hand preference varied inversely with severity of mental retardation. The handedness of mentally retarded groups at the different functional levels paralleled, but tended much more to the sinistral, than that of the corresponding parent groups. The parent-proband handedness correlations were largely insignificant, especially in lower functioning groups. The findings support both pathological left-handedness theory and an association between brain damage causing mental retardation and familial sinistrality.     

Specificity in contrast effects: Judgments of psychopathology

Three experiments were conducted to explore the specificity of the contrast effect in judgments of psychopathology. In the first two studies, respondents initially attempted to infer whether each item in a series of behavior samples (vocabulary definitions in one study, handwriting samples in the second) came from a schizophrenic or a nonschizophrenic patient. Some respondents were presented with highly pathological samples in this induction series, while others were presented with relatively nonpathological samples. These divergent experiences led to marked contrast effects in evaluating test stimuli from the same behavioral domain (e.g., additional vocabulary definitions), but had significantly less impact on the respondent's reactions to stimuli from a different domain (e.g., handwriting samples). A third experiment yielded similar results, using a paired-comparison methodology. In this study subjects first judged a series of high- vs low-pathology definitions. They were then presented with a series of matched stimulus pairs, each including one vocabulary definition and one hand-writing sample. Respondents were to indicate the member of each pair that seemed more indicative of schizophrenia. People assigned to the high-pathology induction group typically chose the handwriting samples as being more indicative of schizophrenia, compared with respondents who were assigned to the low-pathology conditions. These results were interpreted as supporting a representational (perceptual) theory of contrast.     

The relationship of participation in school activities to abilities and interests in a high school student sample

Participation in school activities is hypothesized to be related to the multiple abilities and interests of high school students. The Ball Aptitude Battery (yielding 14 ability scores), Holland's Vocational Preference Inventory, and a biographical information blank (to obtain information about participation in 53 extracurricular activities) were administered to over 900 high school seniors of both sexes. Correlational and multiple regression analyses showed different patterns of activity participation to be related to different abilities and interests. The degree of relationship was generally low, generally higher for the males than for the females, and higher for interests than for abilities. Activity correlates of abilities differed for the sexes, but activity correlates of interests tended to be similar. This suggests that the same ability can result from differential participation in activities, but the same interest develops from similar activities.     

A developmental study of semantic elaboration and interpretation in recognition memory

Two experiments examined semantic elaboration and interpretation in recognition memory of 4-year-olds and college students. Subjects were presented pictures of color-specific and non-color-specific items, and then tested for their recognition of the chroma of the items. In Experiment 1, one-half of the presentation items were black and white and one-half colored, and testing always involved one black and white and one colored choice. In Experiment 2, all of the presentation items were colored, and testing always involved two colored choices. In both studies, the pattern of results of the two age groups was similar. Experiments 1 and 2 indicated that recognition judgments were based on representations that were elaborated with preexperimentally acquired semantic color information, and Experiment 2 also indicated that recognition judgments were based on representations that contained interpretive information about the appropriateness of the colors of the items. The results were considered to support and extend the view that when young children and adults share a common knowledge base, they are likely to engage in similar and extensive semantic processing.     

Input organization as a mediating factor in memory: A comparison of educable mentally retarded and nonretarded individuals

The effect of presentation context on the organization and recall of strongly related and weakly related words was examined in EMR adolescents and nonretarded fifth-grade children of the same mental age (131 months). In blocked presentation formats, subjects sorted words into experimenter-defined groups of four, in which the order of the groupings either changed from trial to trial (i.e., blocked-random), or was consistent across trials (i.e., blocked-consistent). In sort-prompt conditions, subjects were free to structure their own relationships among items during presentation, following instructions to form meaning-based groups (i.e., minimum-sort-prompt), or given explicit training in sorting categorization and sorting stability (i.e., maximum-sort-prompt). Both subject groups found the minimum-sort-prompt method to be as effective as the maximum-sort-prompt method for improving measures of recall and clustering relative to the blocked-random method. Nevertheless, nonretarded children showed higher levels of organization for strongly related items, and better recall and organization for weakly related items. Subsequent analyses suggested that the lower memory performance of the EMR individuals receiving weakly related items was the result of both inconsistent and poorly structured sorting schemes across trials.     

A comparison of parents' models and expansions in promoting children's acquisition of adjectives

This study investigated the effects of parental models plus nondifferential praise and expansions plus nondifferential praise on 2-year-old children's spontaneous use of color and size adjective-noun combinations. Mothers modeled either a color or size adjective-noun combination and expanded the other. Both parental models and expansions increased the children's spontaneous use of the target adjective-noun combinations, but expansions produced a stronger effect than models. These results, and naturalistic data indicating that parents often provide a large number of expansions for their children, suggest that expansions may play an important role in normal language development.     

Intellectual realism in children's drawings of cubes

Ninety-six children copied simple line drawings of perspective views of cubes and similar designs unlikely to be seen as representing objects. The views of cubes were copied much less accurately than the non-object patterns, and the errors made in copying the cubes involved replacement of properties specific to the single perspective view by properties more appropriate to the object itself. Some copies were drawn with the child continually looking at the model and unable to see his own copy, others were drawn in the normal way. Copies made in the former way were more accurate, but even under these conditions cubes were copied less accurately than the non-object patterns. The disadvantage of object pictures, as far as literal copying accuracy is concerned, was still present at 9 1/2 years of age, but was less than at 7 1/2. Two possible explanations are discussed. One is in terms of computational complexity, the other in terms of graphic motor schema. On the basis of the drawings obtained a few suggestions are made about the content and development of the data-structures for cubes.