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.     

Mean response times, variability, and skew in the responding of ADHD children: a response time distributional approach

Response time (RT) distributions from three fixed foreperiod conditions (2, 4, and 8 s) in a warned four-choice RT task were obtained for a group of boys with attention-deficit/hyperactivity disorder, combined type (ADHD; n = 17) and for two groups of normal control boys (age-matched, n = 18, and younger-aged, n = 10). Quantitative measures of distributional shape were derived by fitting the ex-Gaussian distributional model to the individual RT data. Statistical results indicate that the ADHD distributions differ from the age-matched control distributions with respect to the size of the tail (larger for the ADHD boys), but differ from the younger control distributions with respect to the location of the leading edge (slower for the younger control boys). Receiver operating characteristic (ROC) results reveal that the ex-Gaussian exponential component is highly diagnostic of the ADHD boys.     

Some Developmental Implications of Structural Aspects of Preschoolers' Relations with Classmates

To gain insight into children's peer relations and their developmental significance, it is important to know not only how many relations children have but also to consider the structure of these relations. To demonstrate this, we used a multiple-study design in which we applied social network analyses to sociometric ratings and nominations from 1,082 4- to 5-year-old children in 83 school classes. Results showed that isolation in the classroom was more strongly associated with the choices that were given than those that were received. Gender plus the negative behavioral characteristics, aggressiveness and rejection, were the most important cues for social clustering. The structure of positive choices reflected the formation of friendship networks, whereas negative choices tended to be given directly to individual “problem” children. Finally, structure indices tapped aspects of children's relations that were not reflected in the traditional two-dimensional classification system and provided additional explanatory power for predicting developmental outcomes.     

Andrzej de Lazari et al. (eds.), Idei v Rossii/Idee w Rosji/Ideas in Russia; Leksykon rosyjsko-polsko-angielski

Studies in East European Thought -