The effects of consensus requirements and multiple decisions on mock juror verdict preferences

After watching a simulated rape trial, prerecorded on videotape, mock jurors either did or did not expect to sentence a defendant following deliberation with or without a group verdict required. Both sentencing expectation and verdict requirement significantly elevated jurors' preference for conviction (and average ratings of guilt likelihood). Closer analyses of personal changes (before and after deliberation) in the distribution of opinions suggested that majorities favoring not guilty were more influential than guilty-favoring majorities; and, somewhat unexpectedly, minorities in juries which deliberated without a verdict required were more likely to change personal opinions than minorities in juries required to render a verdict. The overall social decision scheme confirmed earlier observations about the importance of the initial majority in determining the verdict; but the majority did not always prevail and there was a marked asymmetry (“defendant protection”) in its action.     

Learning conditional frequencies in a probability learning task

The study was prompted by a theoretical discussion of probability learning by Estes (1976). In three separate experiments, subjects were presented with frequency information in the form of wins and losses among 3 teams, and later predicted future wins and losses. Frequencies were devised so that conditional win frequencies for a pair of teams were either inconsistent or consistent with marginal win frequencies for each team. In experiment 1, when subjects predicted future events on the basis of known past frequencies, predictions were generally based on conditional frequencies. In experiment 2 six blocks of observations were presented, with predictions following each block. What little learning did occur was in the direction of the conditional frequencies. Subjects in experiment 3 were able to learn conditional frequencies when given explicit instructions to do so. Results were discussed in terms of a two-stage hypothesis generation model that might operate within the framework of an associative theory of probability learning.     

Maintenance and generalization of trained metamnemonic awareness by educable retarded children

The majority of educable retarded children (young group, MA 6; old group, MA 8) required to estimate their memory span was found to be unrealistic estimators. Following training in span estimation the older subjects improved under both explicit and implicit feedback conditions, while younger children only benefited from explicit feedback. Three posttests of the effects of training revealed long-term (1-year) maintenance of training for older subjects but younger subjects showed post-test improvement only on an immediate test. While long-term maintenance was found for older subjects, generalization to similar span-estimation tests was not found. The utility of training metamnemonic knowledge which does not generalize was questioned and alternate training procedures were proposed.     

Dimensional asymmetry in attributional inference

A number of bipolar personality dimensions were investigated, some of which were selected a priori as being primarily concerned with interpersonal differences in skill (such as unintelligence-intelligence), and others of which were thought to describe differences in preferences (such as indoor-outdoor). Two findings emerged. First, persons at opposite poles of skill dimensions were assumed to possess differential role-taking ability: a skillful person was perceived as relatively more competent at portraying the opposite behavior than was an unskilled person. Second, attributions based upon skillful behavior tend to be less affected by contextual factors than attributions based upon unskillful behavior. An alternative interpretation of the results is discussed.     

Causes of racial and socioeconomic differences in cognitive tests

Correlations among profiles of means based upon 75 cognitive variables from Project TALENT are presented for groups defined by race, socioeconomic status, sex, area of the country, and grade in high school. Sex makes by far the largest contribution to differences in shape of profiles. Race and socioenconomic status, in turn, make much larger contributions to differences than grade and area. Sex differences in shapes of profiles are a function primarily of race and, to a lesser extent, of social class. Race differences are larger than socioeconomic differences and the former, in particular, are also a function of sex. Black males differ more from white patterns than black females. There is lack of substantial overlap in the causes of race and socioeconomic differences in shape of cognitive profiles.     

Origin of the speech apparatus and its reconstruction in fossils.

Renewed enthusiasm has produced provocative speculations in recent literature on the origin of speech. The purpose of the present investigation is to expose the adaptive renovations underlying the emergence of a “Vocal Tract” and from this to define its anatomical substrate which governs the biomechanics of speech production. The vocal tract is a double resonator tube coupled in series and composed of oral and pharyngeal cavities. Analysis is made of the crucial structural elements of this complex from detailed dissections in modern man and the study of modern and fossil hominid crania. The study focuses on relations of the skull base, jaw, hyoid bone and the contained tongue, pharynx and valvular devices, calling into question recent reconstructions built on classical Neanderthal skulls.     

Task-hemispheric integrity in dual task performance

A condition of task hemispheric integrity is predicted to result in a dual task situation when the central processing and response components of each task are associated exclusively with a given cerebral hemisphere. The prediction that this condition will generate more efficient time-sharing is tested in a series of four experiments. In experiment 1 the prediction is confirmed when a spatial (tracking) and verbal (letter memory search) task are time-shared, and the hand assignment to task responses is manipulated. In experiment 2 a spatial variant of the memory search is used instead of the verbal letter search, and hand assignment effects are not obtained, since when two spatial tasks are time-shared an integrity assignment is impossible. Experiment 3 validates the hemispheric lateralization of the two single task variants of the memory search task, while experiment 4 establishes the separate “spatial’ and “verbal” resource demands of the two variants by observing their differential interference with concurrent spatial and verbal tasks.     

Disfluent speech associated with brain damage

The frequency and type of disfluencies in the spontaneous speech of 15 people with Broca's aphasia and right hemiplegia was studied. Two aged-matched control groups (15 nonaphasic stroke patients with left hemiplegia and 15 normals) were also studied. The frequency of disfluencies in the speech of aphasics was three times greater than that in the speech of either control group. However, most of the disfluencies uttered by aphasics were of the types commonly found in speech of normals.