Resolving the debate over birth order, family size, and intelligence

Hundreds of research articles have addressed the relationship between birth order and intelligence. Virtually all have used cross-sectional data, which are fundamentally flawed in the assessment of within-family (including birth order) processes. Although within-family models have been based on patterns in cross-sectional data, a number of equally plausible between-family explanations also exist. Within-family (preferably intact-family) data are prerequisite for separating within- and between-family causal processes. This observation reframes an old issue in a way that can be easily addressed by studying graphical patterns. Sibling data from the National Longitudinal Survey of Youth are evaluated, and the results are compared with those from other studies using within-family data. It appears that although low-IQ parents have been making large families, large families do not make low-IQ children in modern U.S. society. The apparent relation between birth order and intelligence has been a methodological illusion.     

Counterconditioning in the treatment of spider phobia: effects on disgust, fear and valence

From the perspective that disgust is a core feature of spider phobia, we investigated whether the treatment efficacy could be improved by adding a counterconditioning procedure. Women with a clinically diagnosed spider phobia (N = 34) were randomly assigned to the regular one-session exposure condition (EXP) or to the exposure with counterconditioning condition (CC). In the CC-condition tasty food-items were used during the regular exposure exercises and the participants' favourite music was played. Both treatment conditions appeared very effective in reducing avoidance behaviour and self-reported fear of spiders, strongly attenuated the disgusting properties of spiders and altered the affective evaluations in a positive direction. CC was not more effective in altering the affective valence of spiders than EXP and was not superior with respect to the long term treatment efficacy at 1 year follow up. Apparently, regular exposure treatment is already quite effective in altering the affective-evaluative component of spider phobia and it remains to be seen whether it is possible to further improve treatment outcome by means of procedures which are specifically designed to reduce the spiders' negative affective valence.     

From image segmentation to anti-textons

We apply the 'patchwork engine' (PE; van Tonder and Ejima, 2000 Neural Networks forthcoming) to encode spaces between textons in an attempt to find a suitable feature representation of anti-textons [Williams and Julesz, 1991, in Neural Networks for Perception volume 1: Human and Machine Perception Ed. H Wechsler (San Diego, CA: Academic Press); 1992, Proceedings of the National Academy of Sciences of the USA 89 6531-6534]. With computed anti-textons it is possible to show that tessellation and distribution of anti-textons can differ from that of textons depending on the ratio of texton size to anti-texton size. From this we hypothesise that variability of anti-textons can enhance texture segregation, and test our hypothesis in two psychophysical experiments. Texture segregation asymmetry is the topic of the first test. We found that targets on backgrounds with regular anti-textons segregate more strongly than on backgrounds with highly variable anti-textons. This neatly complements other explanations for texture segregation asymmetry (e.g. Rubenstein and Sagi, 1990 Journal of the Optical Society of America A 7 1632-1643). Second the relative significance of textons and anti-textons in human texture segregation is investigated for a limited set of texture patterns. Subjects consistently judged a combination of texton and anti-texton gradients as more conspicuous than texton-only gradients, and judged texton-only gradients as being more conspicuous than anti-texton-only gradients. In the absence of strong texton gradients the regularity versus irregularity of anti-textons agrees with perceived texture segregation. Using PE outputs as anti-texton features thus enabled the conception of various useful tests on texture segregation. The PE is originally intended as a general image segmentation method based on symmetry axes. With this paper we therefore hope to relate anti-textons with visual processing in a wider sense.     

Differential recall of central and peripheral details of emotional slides is not a stable phenomenon

A number of studies have reported that central information of an emotional scene is well retained, whereas peripheral details of such a scene are poorly recalled. Experiment 1 tested the hypothesis that attentional narrowing is responsible for this phenomenon. In addition, an attempt was made to increase the ecological validity of the experiment by giving extensive self-relevant instructions. Results showed that, although an emotional slide elicited eye-movements consistent with attentional narrowing, the corresponding recall patterns were absent. Experiments 2 and 3 explored some of the variables that might be responsible for the latter result. Experiment 2, relying on the original design of Christianson and E.F. Loftus (1991), found enhanced recall of central information of an emotional scene. Experiment 3 systematically varied stimulus exposure and interstimulus interval durations. However, the results of this experiment were rather complex and did not fully support the predicted differential recall patterns. Possible explanations for these findings are discussed. It is suggested that other methods (e.g. increasing levels of emotion rather than involvement) may be more suitable for testing the attentional narrowing hypothesis of emotional memory.     

A psychometric analysis of chess expertise

This study introduces the Amsterdam Chess Test (ACT). The ACT measures chess playing proficiency through 5 tasks: a choose-a-move task (comprising two parallel tests), a motivation questionnaire, a predict-a-move task, a verbal knowledge questionnaire, and a recall task. The validity of these tasks was established using external criteria based on the Elo chess rating system. Results from a representative sample of active chess players showed that the ACT is a very reliable test for chess expertise and that ACT has high predictive validity. Several hypotheses about the relationships between chess expertise, chess knowledge, motivation, and memory were tested. Incorporating response latencies in test scores is shown to lead to an increase in criterion validity, particularly for easy items.     

Male and female delinquency trajectories from pre through middle adolescence and their continuation in late adolescence

This study of male and female adolescent delinquency trajectories focuses on the prediction of late adolescence delinquency, based on earlier delinquency and social support. In this 3-wave longitudinal survey, 270 Dutch adolescents (113 males and 157 females) ages 12 to 14, were followed for a period of 6 years. For males, the level of delinquent activity in late adolescence strongly depends on earlier delinquent activities (R2 = .33, p < .0005). In contrast, the level of female delinquency in late adolescence is far less predictable (R2 = .18, p < .001), and could not be predicted from delinquent activities during pre and early adolescence, while support from the mother during late adolescence was associated with reduced delinquency for females. Different models may be needed to explain the development of delinquency for males versus females.     

Sustained efficacy of dialectical behaviour therapy for borderline personality disorder

Dialectical Behaviour Therapy (DBT) is considered one of the most promising treatments for borderline personality disorder (BPD). Recently, we reported significantly positive effects of 12 months DBT on parasuicidal behaviour and impulsivity in a mixed group of female BPD patients with and without substance abuse. Fifty-eight women with BPD were randomly assigned to either 52 weeks of DBT or treatment as usual (TAU). Follow-up assessment took place at 78 weeks, i.e., 6 months after discontinuation of DBT. Participants were clinical referrals from addiction treatment and psychiatric services. Outcome measures included parasuicidal behaviour, impulsivity and substance abuse. Six months after treatment discontinuation, the benefits of DBT over TAU in terms of lower levels of parasuicidal and impulsive behaviours, and in alcohol use, sustained. No differences between the treatment conditions were found for drug abuse. In conclusion, DBT seems to have a sustained effect on some of the core symptoms of BPD and on alcohol problems in a mixed population of female borderline patients with and without substance abuse problems.     

A psychometric evaluation of the social skills rating system in children with attention deficit hyperactivity disorder

The social skills rating system (SSRS) was developed to assess social skills of children, as observed by multiple raters (teacher, parent, child). Studies of the SSRS have been conducted with handicapped, mentally retarded and learning disabled children. No studies have reported the psychometric properties of the SSRS in a clinical ADHD sample. This is important, because deficient social functioning is associated with ADHD. The present study assesses the psychometric properties of the teacher, parent and child versions of the SSRS in children with ADHD (n = 123), and normal controls (n = 239). Also, the social skills of children with ADHD, as rated on the SSRS were examined. Results support the factor structure and internal consistency of the original SSRS-teacher version. Moreover, support was found for 3 out of 4 scales of the SSRS-parent version. The factor structure of the SSRS-child version could not be replicated. An explanatory factor analysis on the SSRS-child version yielded two factors. Evidence was found for discriminative ability of the SSRS between normal controls and children with ADHD. Finally, informant agreement between raters was found to be poor.