Some properties of two measures of multivariate association

Two kinds of measures of multivariate association, based on Wilks' and the Bartlett-Nanda-Pillai trace criterionV, respectively, are compared in terms of properties of the univariateR ² which they generalize. A unified set of derivations of the properties is provided which are self-contained and not restricted to decompositions in canonical variates. One conclusion is that asymmetric index based on allows generalization of the multiplicative decomposition ofR ² in terms of squared partial correlations, but not the additive decomposition in terms of squared semipartial correlations, while the reverse is true for anasymmetric index based onV.We are indebted to Jos M. F. ten Berge for some fruitful discussions.     

Comprehension of "absence" by an African Grey parrot: Learning with respect to questions of same/different

An African Grey parrot, Alex, learned to report on the absence or presence of similarity and difference between two objects. Alex was shown pairs of objects that were (a) totally dissimilar, (b) identical, or (c) similar or different with respect to one of three attributes (color, shape, or material). In the first two cases, he responded to the respective queries of “What's same?” or “What's different?” with the vocalization “none,” and in the third case he responded with the appropriate category label (“color,” “shape,” or “mah-mah” [matter]). His accuracy was 80.9% to 83.9% for pairs of familiar objects not used in training and 72.5% to 78.4% for pairs whose colors, shapes, and materials were unfamiliar. The data provide evidence that this parrot's abilities are comparable to those of mammals that have been trained to report on the presence or absence of objects or features of objects.     

Correspondence in children's self-report: Tacting and manding aspects

Four boys and 4 girls (3 to 5 years old) played with as many as three toys chosen from a set of six, and were then asked whether they played with each of the toys. After a baseline in which all children showed high levels of correspondence between reported and actual behavior, reports of play were differentially reinforced, first in an individual and then in a social context. Two children in the individual condition began to report play with all six toys, even though no more than three toys had been played with. When reports of play were reinforced in a group context, 5 children reported play with all six toys. When correspondence was subsequently reinforced, virtually complete correspondence returned and was maintained in a third noncontingent reinforcement condition. Correspondence and lack of correspondence were discussed in terms of self-tacting and distorted tacting or manding.     

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.     

What is told when the story is retold? Consistency of victimization reports in psychiatric patients

The use of retrospective self‐reports is a major methodological concern when ascertaining the occurrence of victimization experiences, with additional concerns when assessing psychiatric patients. The test for consistency can overcome some of these concerns, increasing the confidence in the information reported. Our aim was twofold: (1) to know the consistency of victimization reports; and (2) to test the role of changes on emotional distress in predicting report discrepancies, in a sample of 34 adult psychiatric patients. Participants were assessed twice, with a year interval. Sexual abuse was the experience that presented the higher level of consistency for childhood victimization, while assault with a weapon had the higher consistency level for adolescent and adult victimization. We found that increases on emotional distress predicted report discrepancies, and more specifically, increases in the report of victimization. Our results displayed acceptable consistency levels, suggesting some stability in the reporting of victimization over time. Considering that inconsistencies tended either to increases and decreases in the reporting of victimization, it would be important to consider the impact of such experiences when intervening with psychiatric patients.