Causal models of adolescent substance use: an examination of gender differences using distribution-free estimators

On the basis of previous literature (Hays, Widaman, DiMatteo, & Stacey, 1987; Huba, Wingard, & Bentler, 1981), four alternative causal models of substance use were specified, estimated, and evaluated for adequacy of statistical fit for samples of White male (N = 9,164) and female (N = 8,421) adolescents. Results supported the adequacy of a four-variable simplex model, in which alcohol use predicted marijuana use, and marijuana use predicted enhancer and dampener hard drug use. The four-variable simplex model was robust across the male and female adolescent samples. In addition, we found comparisons of maximum likelihood and asymptotically distribution-free estimators to be relatively robust across the causal models specified with respect to the magnitude of the parameter estimates, and with respect to the significance levels of the critical ratios, although chi-square model fit statistics for the maximum likelihood estimates were highly inflated.     

Determinants of the rod-and-frame effect: Role of organization and subjective contour

In Experiment 1, performance on a conventional (full) rod and frame was compared with that on three other displays. These included a closure condition in which only the corners of a luminous frame were present, a subjective contour condition in which the rod was seen against ablack square subjective surface, and a pattern condition in which four luminous disks were arranged to form the corners of a square pattern. In all cases, a square-like form was perceived. The rod-and-frame effect (RFE) was greatest on the full frame, which differed significantly from all the rest. Closure produced the next greatest influence, while the responses to subjective and pattern conditions did not differ from each other. Experiment 2 showed that a subjective frame was no more effective than the subjective surface of Experiment 1, and verified the importance of 90-deg corner elements in the rod-and-frame display. The conclusion drawn was that equivalent form organizations are not sufficient to produce equivalent levels of the RFE, but certain luminance-difference contours appear to be essential.     

The effect of light intensity when onset or termination of illumination is used as reinforcing stimulus

The Psychological Record - Two experiments were performed to examine the reinforcing effects of onset and termination of non-aversive illumination, made conterminous with lever contacting, as a...     

Misperception Among Gay Men of the Risk for AIDS Associated with Their Sexual Behavior1

Until a vaccine against AIDS is developed, the most effective strategy for preventing the spread of the disease among gay men, the largest risk group, is to persuade them to abstain from particular kinds of sexual practices implicated in the transmission of the AIDS virus. Motivation to comply with risk-reduction guidelines, however, is dependent in part on a realistic appraisal of the degree of risk associated with one's sexual practices. Data are presented from 160 asymptomatic gay men. Their subjective assessment of the riskiness of their sexual behavior is compared to an objective assessment of the riskiness of their sexual practices. Factors associated with a tendency to underestimate the riskiness of one's practices are examined. Finally, the implications of the findings for public health education efforts among gay men are discussed.     

Longitudinal analysis of the relationship between changes in smoking and changes in drinking in a community sample: the Winnipeg Health and Drinking Survey.

Smoking cigarettes and drinking alcohol are positively correlated in cross-sectional studies of the general population. However, it is unclear whether changes in quantity of drinking over time are related to changes in amount of smoking over time. This investigation examined, with structural equation modeling, the relationship of changes in drinking to changes in smoking over 2 years among 344 adults who reported cigarette smoking and alcohol use at baseline in 1989-1990 or at follow-up in 1991-1992 or both. Surprisingly, no significant relationships were found between changes in smoking and changes in drinking. This lack of effect suggests that changes in the quantity or intensity of drinking and of smoking are not related in any important way in nonclinical populations.     

FEMINISM AND WOMEN'S FRIENDSHIPS

The ideology of "sisterhood" within the feminist movement suggests that feminists' and nonfeminists' same–sex friendships would differ profoundly. This assumption was tested by examining the friendships of 45 heterosexual nonfeminists, 43 heterosexual feminists, and 38 lesbian feminists from a large midwestern city. Participants ranged in age from 19 to 46. Using objective measures, differences were found between feminists and nonfeminists for some structural dimensions of friendship, including number of cross–generational friendships, degree of equality, and amount of privacy preferred with a best friend. Lesbian feminists preferred more privacy with their friends than nonfeminists, but rated their friends as lower on relationship quality and degree of equality than heterosexual feminists and nonfeminists. The three groups did not differ on the affective content of friendship, including liking, loving, satisfaction and commitment. However, feminists subjectively perceived their feminism as having contributed to both structural and affective changes in their friendships.     

Neuroanatomical correlates of performance in a state‐wide test of math achievement

The development of math skills is a critical component of early education and a strong indicator of later school and economic success. Recent research utilizing population‐normed, standardized measures of math achievement suggest that structural and functional integrity of parietal regions, especially the intraparietal sulcus, are closely related to the development of math skills. However, it is unknown how these findings relate to in‐school math learning. The present study is the first to address this issue by investigating the relationship between regional differences in grey matter (GM) volume and performance in grade‐level mathematics as measured by a state‐wide, school‐based test of math achievement (TCAP math) in children from 3rd to 8th grade. Results show that increased GM volume in the bilateral hippocampal formation and the right inferior frontal gyrus, regions associated with learning and memory, is associated with higher TCAP math scores. Secondary analyses revealed that GM volume in the left angular gyrus had a stronger relationship to TCAP math in grades 3–4 than in grades 5–8 while the relationship between GM volume in the left inferior frontal gyrus and TCAP math was stronger for grades 5–8. These results suggest that the neuroanatomical architecture related to in‐school math achievement differs from that related to math achievement measured by standardized tests, and that the most related neural structures differ as a function of grade level. We suggest, therefore, that the use of school‐relevant outcome measures is critical if neuroscience is to bridge the gap to education.