An empirical comparison of theZ-variance and Box-Scheffé tests for homogeneity of variance

This brief report provides a comparison of theZ-variance and Box-Scheffé tests for homogeneity of variance. Both procedures are relatively simple to perform and both may be readily utilized in complex, multifactor designs. TheZ-variance test is not robust against non-normality; the Box-Scheffé test is robust against non-normality but is not nearly as powerful as theZ-variance test.     

DOMINANCE AND INEQUALITY IN X-RATED VIDEOCASSETTES

Feminists have been concerned about the debasement of women in sexually explicit material. The purpose of this study was to determine the extent of domination and sexual inequality in x-rated videocassettes through a content analysis of 45 widely available x-rated videocassettes. The sample was randomly drawn from a list of 121 adult movie titles widely available in family videocassette rental stores in southern California. Over half of the explicitly sexual scenes were coded as predominantly concerned with domination or exploitation. Most of the domination and exploitation was directed by men toward women. Specific indicators of domination and sexual inequality, including physical violence, occurred frequently. The growth of the videocassette rental industry and the popularity of x-rated films, coupled with the messages these films convey, is a cause for concern.     

The effects of essential fatty acid supplementation by efamol in hyperactive children

Thirty-one children, selected for marked inattention and overactivity, were studied in a double-blind, placebo-controlled crossover study of essential fatty acid (EFA) supplementation. Subjects received the active treatment and placebo conditions for 4 weeks each and were assessed on a variety of cognitive, motor, and standardized rating scale measures. EFA supplementation (evening primrose oil; Efamol®) resulted in significantly lower levels of palmitoleic acid (a nonessential fatty acid) and higher concentrations of dihomogammalinolenic acid, an EFA previously found to be deficient in some hyperactive children. Supplementation was also associated with significant changes on two performance tasks and with significant improvement to parent ratings on the subscales designated as Attention Problem and Motor Excess of the Revised Behavior Problem Checklist. However, a variety of eight other psychomotor performance tests and two standardized teacher rating scales failed to indicate treatment effects. When the experimentwise probability level was set at.05, only 2 of 42 variables showed treatment effects. Baseline EFA concentrations appeared to be unrelated to treatment response. It was concluded that EFA supplementation, as employed here, produces minimal or no improvements in hyperactive children selected without regard to baseline EFA concentrations.This study was supported by grants from Efamol Research Inc., and the Medical Research Council of New Zeland. We thank Messers. Patrick Flynn and Mark Norwood for carrying out the statistical analyses.     

Homicide and the insanity defense: A comparison of sane and insane murderers

A sample of 50 homicide defendants acquitted by reason of insanity (NGRI) was compared with a group of 50 defendants who were evaluated for insanity and found to be criminally responsible (CR). Significant differences were found between the two groups in terms of prior psychiatric and criminal histories and nature of the homicide (i.e., relationship to victim). The dispositions of those found NGRI were also examined on the above variables.     

Reading,spelling, and vigilance in attention deficit and conduct disorder

A group of 51 male children, average age 9.1 years, presenting at a child psychiatric clinic because of attention and conduct problems were investigated for reading and phonetic spelling ability, vigilance, and intellectual level. Each child was given a DSM- III diagnosis prior to being tested. The Boder Test of Reading and Spelling patterns was used to obtain scores for reading age, number of syllables read correctly in the word list at the child's reading level, and number of phonetically correct syllables spelled in the known and unknown word lists, at and just above the child's reading level. A factor analysis with varimax rotation produced two significant factors, a Reading factor with high loadings for verbal and reading scores, aand a second Vigilance factor. Phonetic spelling ability loaded separately from reading into the Vigilance factor. The Vigilance factor was significantly related to the diagnosis of moderate and severe attention deficit disorder with hyperactivity (ADDH). The correlation of short- term working memory with vigilance in moderate to severe ADDH children is discussed.Fundling assistance was provided by the New South Wales Institute of Psychiatry.     

State vs trait anxiety: A case study in confirmatory factor analysis

The State-Trait Anxiety Inventory (STAI; Spielberger et al., 1970) originally divided anxiety into two factors: state anxiety, reflecting how an individual currently feels, and trait anxiety, reflecting how an individual generally feels. Recently, however, Spielberger revised his position to separate the presence and absence of anxiety symptoms within state and trait factors, yielding a hypothetical correlated 4-factor structure (Spielberger et al., 1980). Endler and Magnusson (1965) and Endler et al. (1976) have challenged the state vs trait distinction based upon their own factor analytical results. Since both sets of investigations used exploratory approaches, which do not postulate a particular factor structure, these studies do not provide an explicit test of the state vs trait distinction. A confirmatory factor analytic approach was used in the present study to evaluate Spielberger's 4-factor hypothesis. The subjects were large samples of male air force trainees and high school students for whom STAI data were available. The results of these confirmatory analyses indicated that the factors identified in exploratory analysis by Spielberger and his colleagues accounted for the data quite well.     

Premarital sexual intercourse among single college students: A discriminant analysis

This study assesses the relative importance of interpersonal psychological variables in the prediction of the number of premarital sexual partners of single college students. Using data from a sample of 466 college students from a large mid-Atlantic university, various discriminant functions were formulated and used to predict a student's premarital sexual partners group membership. A virgin group, a monogamous group, a moderate partners group, and a extensive partners group were identified. The variables selected by the computer for inclusion in the functions are of theoretical importance. Males and females differed in the sets of weighted variables chosen by the computer to enter the discriminant functions. Different functions were found to best discriminate the virgin group from the monogamous group, the moderate partners group, and the extensive partners group, especially for males. When subjects were reclassified using the discriminant functions, the predictive accuracies were significantly increased above chance in 14 instances of reclassification. The data support the view that male and female single college students are moving toward an equal standard with regard to premarital intercourse behavior. However, the interpersonal psychological correlates of sexual intercourse appear to be quite different for males and females. Male variation along the power or dominance dimension of Leary's Interpersonal Adjective Checklist was most reflective of their sexual partners group, while females were best discriminated using variables related to the affiliation or affection dimension. A three-stage theory of normative change is formulated to explain the existing data.