Handedness and sex differences in hemispheric asymmetry

A study was designed to assess the contributions of the factors of sex and familial history to cerebral dominance, where cerebral dominance was inferred from laterality on a dichotic listening task. The 144 subjects were selected from a larger sample on the basis of handedness, sex, and familial history of sinistrality, and tested on a task involving the dichotic presentation of CV syllables. Analysis of the data indicated that in female subjects, the presence of familial sinistrality increased the likelihood that they present atypical left-ear superiorities, while in males the converse was the case. Moreover, there was a significant sex difference overall, such that males were more clearly lateralized than females. A review of other dichotic listening studies provided support for the reliability of this sex difference for dichotic tasks using verbal material. A review of the clinical literature indicated that the hypothesis of a sex difference is at least tenable and merits further investigation. However, the possibility that there is a sex difference in the cognitive strategy used in dichotic listening cannot be ruled out.     

Study habits and Eysenck's theory of extraversion-introversion

Predictions derived from Eysenck's theory of personality were tested in two samples by relating extraversion scores to library study locations, frequency of study breaks, and self-report of factors which influence study location. The predicted main effects for study location were found, with extraverts occupying locations that provided greater external stimulation. Positive correlations were consistently found between extraversion and preferred level of noise, preferred level of socializing opportunities, and rated importance of socializing opportunities. The prediction that extraverts would take more frequent study breaks was supported in Sample 1 but not replicated in Sample 2. The data are interpreted as providing direct support for Eysenck's theory of behavioral differences and mixed indirect support for his theory of neurological differences between introverts and extraverts.     

Differences in matching-to-sample performance with element and compound sample stimuli in pigeons

This series of experiments examined zero-delay matching-to-sample performance in pigeons with element and compound sample stimuli. In Experiment 1, compound sample stimuli were consistently followed by compound comparison stimuli and matching accuracy during testing was equivalent to element sample-element comparison trials on the color dimension. In Experiment 2, element comparisons suddenly introduced following compound samples produced a decrement on the line dimension only. Subsequent testing at various sample durations revealed higher matching accuracy following element samples than following compound samples on both the color and line-tilt dimensions. Experiment 3 replicated the results of Experiments 1 and 2 and also demonstrated that the superiority of element over compound matching performance remains constant over the sample durations tested. In Experiment 4 testing at sample durations up to 30 sec produced an overall decrement in matching performance, but again the element vs compound matching difference remained constant. The stimulus-generalization decrement hypothesis provided a better explanation of these results than either the information-overload hypothesis or the rule hypothesis.     

Communicative gestures of the hand and arm when 4-year-old sons and their mothers interact

This study investigated a wide range of communicative hand/arm gestures of 4-year-old males when interacting with their mothers. The types of gesture categories observed were in keeping with the predicted encoding ability of this aged child. Pantomimic and deictic gestures were observed in significantly greater numbers than semantic modifying and relational gestures. Although it was found that the mothers' gestural usage reflected the type of gesture categories seen in the children's group, no correlation was found between gesture usage of individual mother-child pairs.     

The purposes of laboratory experimentation and the virtues of deliberate artificiality

Critics of the laboratory experiment have maintained that artificiality (the intrusion into the experiment of “unrealistic” conditions) vitiates any possibility of generalizability beyond the confines of the laboratory. It is argued here that such artificiality in laboratory experimentation is a defect or flaw only within the context of verification and may be a distinct virtue in the context of discovery. Indeed it is argued that social psychological experiments may not be artificial enough when contrasted with the most fruitful experiments in the natural sciences. One purpose of an experiment may be to maximize artificiality deliberately so as to discover regularities that do not presently obtain under the “real” conditions outside the laboratory but which are capable of existing. When such observed laboratory regularities produce potentially beneficial outcomes, an attempt may be made to create the specific artificial laboratory conditions outside the laboratory to benefit mankind. This logic, exceedingly common in the natural sciences, has been virtually ignored in social psychology, even in the laboratory experiment, in favor of “realistic” reproduction of existing or reasonably plausible situations. Theoretical benefits of this additional modality of experimentation are illustrated by two recent developments in psychology.     

Levels in the identifying of orientation by preschool children

A new approach to understanding the perception of orientation proposes that the first level in the processing of orientation information results in perceiving whether a shape is upright or nonupright; nonupright orientations are not distinguished from each other. As predicted, children of 3 and 4 years discriminated upright from nonupright pictures more readily than they discriminated the nonuprights (upside down and sideways) from each other. The angular differences between the pairs of discriminanda (whether 90 or 180°) had no effect on performance. the difficulty of distinguishing between nonuprights could not be attributed simply to a lack of attention to the dimension of orientation. The theory appears to have considerable generality, and provides a basis for understanding (1) perception of the orientation of both realistic and geometric shapes, and (2) similarities in orientation perception observed between children and adults.     

Sign-tracking in aversive conditioning

Two experiments were conducted to determine if rats tend to avoid contact with a stimulus that signals the occurrence of shock and contact a stimulus that signals the nonoccurrence of shock. The conditioned stimulus was a 60-sec platform presentation, and the unconditioned stimulus was a 2-sec inescapable shock. In each experiment, the emphasis was on two types of Pavlovian pairings: forward pairing in which each platform presentation was followed by shock, and backward pairing in which each platform presentation was preceded by shock and followed by a lengthy shock-free interval. Experiment 1 showed that in comparison with Random and CS-only procedures, the backward procedure produced a significant increase in approach and contact with the platform, but the forward procedure failed to produce a significant decrease in contact with the platform. Experiment 2, in which all groups were roughly equated for baseline levels of platform preference, demonstrated strong effects of both forward and backward conditioning. The experiments provide evidence for an aversive sign-tracking system in which animals' tendencies to withdraw from or approach and contact a platform CS are determined by the Pavlovian contingencies which render it a reliable signal for the occurrence or nonoccurrence of shock.     

Interpersonal problem solving as a mediator of behavioral adjustment in preschool and kindergarten children

An experimental model tested the mediating function of interpersonal cognitive problem solving skills on behavioral adjustment in preschool and kindergarten children. Relative to controls, nursery-trained youngsters improved in three such skills, kindergarten-trained in two. In both the nursery- and kindergarten-trained groups, increased ability to conceptualize alternative solutions to interpersonal problems significantly related to improved social adjustment. Consequential thinking also emerged as a clear behavioral mediator, especially among kindergarten-aged youngsters. Improvement in behavior could not, however, be attributed to change in causal thinking skills. Having identified two significant behavioral mediators in young children, a beginning has been made to isolate specific thinking skills, which, if enhanced, can contribute to healthy social adjustment and interpersonal competence at an early age.