Performance on a mirror-drawing task by non-right-handers

Left-, mixed-, and right-handed (each n = 10, N = 30) adolescent boys who were classified on the basis of a hand preference inventory performed a mirror-drawing task with a bilateral transfer of a skill paradigm. Participants' hand preference and the magnitude of bilateral transfer of skill were assessed in terms of errors committed and time taken to complete the mirror-drawing task. Mixed-handed participants exhibited significantly less habit interference for mirror drawing, and they performed the task significantly faster than the left-handers did; the group difference was not significant for the frequency of errors committed. These groups did not differ in terms of the magnitude of bilateral transfer of skill; the trend, however, showed that the transfer of skill was minimum in mixed-handers. These findings extend the theory that mixed-handed participants' inability to transfer motor skill from one hand to the other could be attributable to their lack of a clear pattern of lateralization. Their ability to perform well either at initial or later trials may be a function of less interference from their normal motor habits.     

Numerical and arithmetical cognition: a longitudinal study of process and concept deficits in children with learning disability

Based on the stability and level of performance on standard achievement tests in first and second grade (mean age in first grade = 82 months), children with IQ scores in the low-average to high-average range were classified as learning disabled (LD) in mathematics (MD), reading (RD), or both (MD/RD). These children (n = 42), a group of children who showed variable achievement test performance across grades (n = 16), and a control group of academically normal peers (n = 35) were administered a series of experimental and psychometric tasks. The tasks assessed number comprehension and production skills, counting knowledge, arithmetic skills, working memory, the ease of activation of phonetic representations of words and numbers, and spatial abilities. The children with variable achievement test performance did not differ from the academically normal children in any cognitive domain, whereas the children in the LD groups showed specific patterns of cognitive deficit, above and beyond the influence of IQ. Discussion focuses on the similarities and differences across the groups of LD children.     

Gender bias in mothers' expectations about infant crawling

Although boys outshine girls in a range of motor skills, there are no reported gender differences in motor performance during infancy. This study examined gender bias in mothers' expectations about their infants' motor development. Mothers of 11-month-old infants estimated their babies' crawling ability, crawling attempts, and motor decisions in a novel locomotor task-crawling down steep and shallow slopes. Mothers of girls underestimated their performance and mothers of boys overestimated their performance. Mothers' gender bias had no basis in fact. When we tested the infants in the same slope task moments after mothers' provided their ratings, girls and boys showed identical levels of motor performance.     

Confirmatory factor analyses of the full and short versions of the Marlowe-Crowne Social Desirability Scale

Over the years, researchers have developed various short versions of the Marlowe-Crowne Social Desirability Scale (D. P. Crowne & D. Marlowe, 1960). The authors used confirmatory factor analyses (J. L. Arbuckle, 1997) as well as item and scale analyses to evaluate the adequacy of the full version and various short versions. Overall, the results from 232 Canadian undergraduates showed (a) that all the short versions in the present study are a significant improvement in fit over the 33-item full scale and (b) that W. M. Reynolds's (1982) Forms A and B are the best fitting short versions. No gender differences were found for the full scale or any of the short versions. The results show that the full scale could be improved psychometrically and that the psychometrically sound short versions should be available because they require less administration time than the full scale.     

The Mackworth Clock Test: a computerized version

The Mackworth Clock Test (MCT; N. H. Mackworth, 1948) was developed to evaluate vigilance in British Air Force radar technicians during World War II. Homemade versions of the MCT have since varied with respect to both the characteristics of the device and the procedures of its administration. This article is a report on a computerized version of the MCT developed by the authors to closely emulate Mackworth's test. MCT data were collected from 25 undergraduate students; their performance was found to be equivalent to Mackworth's participants' data. This is the first MCT version that has been validated against the original.     

Comparison of selected perceptual variables for backpacks with internal and external frames

Differences in perceptions of comfort, exertion, balance, and heart rate were investigated with two types of backpack. Subjects were 20 male volunteers (M age = 24.3 yr., SD: 3.6, M height = 180.02 cm, SD: 8.0, and M weight = 86.46 kg, SD: 14.84). Following oral briefing and practice trials, each subject was fitted at random with either an internal- or external-frame backpack containing 18.2 kg. By random, cross-over design, subjects completed a 30-m simulated hiking trial consisting of 16 separate obstacles designed to resemble actual off-trail hiking. Trials were conducted in a controlled environment with the walking intensity regulated by a metronome. Upon completion of each trial, the subjects rated the experience on perceived comfort, balance and stability, and rating of perceived exertion. Heart rate was recorded immediately prior to and following each trial. Analysis yielded a significant difference only on rating of perceived exertion in favor of the internal-frame backpack. Under limited circumstances, these data suggest that both types of backpacks provide similar comfort and balance and stability; however, internal frames in backpacks may reduce perceived exertion during short, demanding hikes.     

The Terpstra-Jonckheere test for ordered alternatives: randomized probability values

An algorithm and FORTRAN program are presented for the Terpstra-Jonckheere test statistic and associated probability value based on a randomization routine.     

Attribution of aggression to acts: a four-factor model

Factors determining why acts are regarded as aggressive were investigated in a sample of 303 subjects (140 males, 163 females, M age = 17.7 yr., SD = 1.4). A model was tested, according to which people base their attribution of aggression to acts on four factors: (1) intention (yes/no), (2) reason (attack/defense), (3) injury (death/injury/no injury), and (4) mode (weapon/bare hands/nonphysical means). All four factors contributed to the explanation of attribution of aggression, and the order of importance was the one mentioned above, intention being most important. The interaction between intention and reason was the second most important, contributing more than reason alone. The findings are consistent with the severity of punishment in sentences for different crimes of violence.     

Opinion on AIDS prevention and education among rural secondary school pupils in the northern province of South Africa

The study investigated perceptions of AIDS prevention and education among 308 Grade 11 pupils (132 boys and 176 girls), secondary school pupils (mainly Northern Sotho and Tsonga) in the Northern Province of South Africa. They were chosen randomly from three rural schools in Mankweng district and were ages 17 to 25 years (M age = 19.1 yr., SD = 2.8). Analysis of ratings given on items of a questionnaire on AIDS prevention and education indicated that 'Isolating people who are HIV positive' and 'How to protect yourself from getting HIV/AIDS' received the highest ratings. Factor analysis extracted three factors on AIDS education explaining 48% of the variance. The items loading strongly on the first factor were use of condoms (.54), giving information (.53), finding a cure (.52), and no sex outside marriage (.42). On AIDS education two factors were extracted accounting for 52% of the variance. The first factor had significant item loadings for 'sexual behaviour and HIV/AIDS' (.75), 'knowledge of self-protection' (.68), 'how AIDS/HIV affects the body' (.66), and 'alcohol and sexual behaviour'. These findings should contribute to the development of health promotion initiatives directed at AIDS/HIV.     

Measuring self-efficacy among drug-involved probationers

Self-efficacy has been shown to be related to outcomes from interventions for alcohol and tobacco abuse but relatively little attention has been focused on it in evaluations of treatment for illicit drug abuse. Almost no research has examined offenders involved with drugs. The current study, therefore, adapted the Alcohol Abstinence Self-efficacy Scale of DiClemente, Carbonari, Montgomery, and Hughes and administered it to 250 probationers mandated to 6 months of residential treatment. With some modifications, confirmatory factory models replicated four previously reported dimensions, e.g., Negative Affect, Social/Positive, Physical and Other Concerns, Cravings and Urges. Findings also indicated high construct validity for the Alcohol Abstinence Self-efficacy Scale as adapted here. Studies are needed to examine the use of self-efficacy as a prospective measure of treatment progress and to explore its association with outcomes from corrections-based treatment.