Adverse effects of predictive testing for Huntington disease underestimated: long-term effects 7-10 years after the test.

The 7-10-year psychological effects of presymptomatic testing for Huntington disease are described in 142 individuals and 104 partners. Questionnaires included the Beck Hopelessness Scale (A. T. Beck, A. Weissman, D. Lester, & L. Trexler, 1974), the Impact of Event Scale (M. J. Horowitz, N. Wilner. & W. Alvarez. 1979). and the General Health Questionnaire (D. P. Goldberg. 1972). Carriers and their partners were more distressed immediately after the test result, although their outlooks improved somewhat in the 2-3-year posttest period. However, they became more pessimistic thereafter, when approaching the age of onset. Carriers, who were lost to follow-up after disclosure of test results, reported more distress pretest than did retained carriers. This demonstrates that studies that report few harmful effects may have underestimated the real impact. Moreover, follow-up studies need to investigate time effects for longer than a few years.     

Establishing the constructs of childhood behavioral disturbances in a Chinese population: A questionnaire study

The behavioral problems of Chinese children were examined in a questionnaire study of a representative sample of 3,069 seven-year-old Chinese schoolboys in Hong Kong using Rutter's questionnaires for completion by parents and teachers. Separate robust dimensions of hyperactivity, antisocial, and neurotic behaviors were evident. The correlations among different dimensions were similar to those reported in the West. Short-term longitudinal analysis suggested that these dimensions were stable over time and that antisocial behaviors might develop in hyperactive children. The finding highlights the necessity of differentiating the hyperactive domain from the antisocial one. A significant source effect was found in all three dimensions. Chinese schoolboys had nearly two times the level of questionnaire-rated hyperactivity compared with school boys in the West; but it is premature to conclude that hyperactivity is more common in Chinese schoolboys in Hong Kong. Cross-cultural differences in adults' expectations and tolerance remain a plausible explanation.This study was supported by the Croucher Foundation. We would like to thank the Education Department of Hong Kong for assistance in sampling. We are particularly grateful to the children, teachers, and parents who participated in this study.     

Evaluating Müller-Lyer effects using single fin-set configurations

Four experiments were conducted to study the bias of perceived length for Müller-Lyer configurations that contained a single set of fins (i.e., two segments that join to form a vertex). The experiments manipulated several factors that have been shown to be critical to the effect: (1) version (which way the apex pointed), (2) length of the stimulus span, (3) presence or absence of a line segment in the span being judged, (4) fin length, (5) fin angle, and (6) the zone in which the response was rendered. Using percent error as the index of perceptual distortion, the major finding was that the two versions show an opposite slope for strength of effect as a function of span. When stimulus spans were plotted against response means (not converting to percent error), an almost perfect linear relation was found. These results indicate that the perceptual effects can be modeled as a linear system having two parameters through which the treatments exert their influence. The results are discussed in relation to major theories of mechanism for the Müller-Lyer illusion.     

A theory of appropriate statistics

A formal theory of appropriateness for statistical operations is presented which incorporates features of Stevens' theory of appropriate statistics and Suppes' theory of empirical meaningfulness. It is proposed that a statistic be regarded as appropriate relative to statements made about it in case the truths of these statements are invariant under permissible transformations of the measurement scale. It is argued that the use of inappropriate statistics leads to the formulation of statements which are either semantically meaning-less or empirically nonsignificant.This research was supported in part by each of the following grants: National Science Foundation Grant GS-333 to the University of Oregon; National Science Foundation Grant to the Institute of Human Learning, University of California, Berkeley; and National Institute of Mental Health Grant MH-08055-01 (under the direction of Ernest W. Adams), also to the Institute of Human Learning. Work on this project was carried out in part during Robert F. Fagot's tenure as Public Health Service Special Fellow (No. MSP-15800) at the University of California, Berkeley, 1962-63; and during Richard E. Robinson's tenure as National Science Foundation Science Faculty Fellow at Stanford University, 1962–63.