Studies of a Child. I

The authors examined the relationship between newborn neurobehavioral profiles and the characteristics of early mother-infant interaction in Nagasaki, Japan. The authors administered the Brazelton Neonatal Behavioral Assessment Scale (NBAS; T. B. Brazelton &; J. K. Nugent, 1995) in the newborn period and the Nursing Child Assessment Teaching Scale at 1 month (NCATS; G. Sumner &; A. Spietz, 1994). They administered the Perceived Stress Scale (S. Cohen, T. Kamarck, &; R. Mermelstein, 1983) as an index of maternal stress experienced over the past month. Lower irritability, higher stability in skin coloration, and lower tremulousness in the neonatal period were correlated with higher levels of maternal nurturing behaviors at 1 month. Birth weight and 2 NBAS range-of-state items (peak of excitement, irritability) predicted 31% of the variance in NCATS caregiver subscale score. The NBAS autonomic stability items (tremulousness, startles, lability of skin color) predicted 31% of the variance in the NCATS child subscale score. Perceived stress and maternal sociodemographic variables (education, income, age, parity) were not associated with child, caregiver, and total scores on the NCATS. The results suggested that lack of autonomic stability in Japanese neonates might serve as an early indicator of infant frailty, negative behavioral cues, and decreased maternal responsiveness.     

Analytical Inverse Optimization in Two-Hand Prehensile Tasks

The authors explored application of analytical inverse optimization (ANIO) method to the normal finger forces in unimanual and bimanual prehensile tasks with discrete and continuously changing constraints. The subjects held an instrumented handle vertically with one or two hands. The external torque and grip force changed across trials or within a trial continuously. Principal component analysis showed similar percentages of variance accounted for by the first two principal components across tasks and conditions. Compared to unimanual tasks, bimanual tasks showed significantly more frequent inability to find a cost function leading to a stable solution. In cases of stable solutions, similar second-order polynomials were computed as cost functions across tasks and condition. The bimanual tasks, however, showed significantly worse goodness-of-fit index values. The authors show that ANIO can be used in tasks with slowly changing constraints making it an attractive tool to study optimality of performance in special populations. They also show that ANIO can fail in multifinger tasks, likely due to irreproducible behavior across trials, more likely to happen in bimanual tasks compared to unimanual tasks.     

Using Score Equating and Measurement Invariance to Examine the Flynn Effect in the Wechsler Adult Intelligence Scale

The Flynn effect (FE; i.e., increase in mean IQ scores over time) is commonly viewed as reflecting population shifts in intelligence, despite the fact that most FE studies have not investigated the assumption of score comparability. Consequently, the extent to which these mean differences in IQ scores reflect population shifts in cognitive abilities versus changes in the instruments used to measure these abilities is unclear. In this study, we used modern psychometric tools to examine the FE. First, we equated raw scores for each common subtest to be on the same scale across instruments. This enabled the combination of scores from all three instruments into one of 13 age groups before converting raw scores into Z scores. Second, using age-based standardized scores for standardization samples, we examined measurement invariance across the second (revised), third, and fourth editions of the Wechsler Adult Intelligence Scale. Results indicate that while scores were equivalent across the third and fourth editions, they were not equivalent across the second and third editions. Results suggest that there is some evidence for an increase in intelligence, but also call into question many published FE findings as presuming the instruments' scores are invariant when this assumption is not warranted.     

Ramseyan Humility, scepticism and grasp

In ‘Ramseyan Humility’ David Lewis argues that a particular view about fundamental properties, quidditism, leads to the position that we are irredeemably ignorant of the identities of fundamental properties. We are ignorant of the identities of fundamental properties since we can never know which properties play which causal roles, and we have no other way of identifying fundamental properties other than by the causal roles they play. It has been suggested in the philosophical literature that Lewis’ argument for Humility is merely an instance of traditional scepticism, to which traditional responses to scepticism are applicable. I agree that in ‘Ramseyan Humility’ Lewis does present an argument to which it is appropriate to consider the applicability of responses to traditional scepticism—he argues that we irredeemably lack the evidence to rule out possibilities in which different properties occupy the causal roles described by our best physical theory. And prima facie this is just the kind of argument responses to traditional scepticism are designed to tackle. However, I will argue that Lewis bolsters this argument with a second. This second argument serves to deepen Lewis’ case and cannot be met with a response to traditional scepticism. For Lewis argues that not only do we lack evidence for which properties play which roles, we lack the ability to grasp any such proposition about role-occupancy. And if we cannot grasp any such proposition we cannot know it.     

An item-level examination of the Flynn effect on the National Intelligence Test in Estonia

This study examined the Flynn effect (FE; i.e., the rise in IQ scores over time) in Estonia using the Estonian version of the National Intelligence Tests (NIT;  and ). Using secondary data from two cohorts (1934, n = 890 and 2006, n = 913) of students, we analyzed the NIT's subtests using item response theory (IRT). For each subtest, we first examined invariance in all the items and then linked the latent variable (θ) scores between the two cohorts using the invariant items. The results showed that there was a FE in θ for all subtests except one, although there was much variability in the FE magnitude, ranging from an effect size of 0.24 (3.60 IQ points) to 1.05 (15.75 IQ points). In addition, this study showed there was a decrease in the variability of θ for all the subtests, although only two of the subtests showed large decreases (approximately .50 standard deviations). Last, the subtests' precision of measuring θ was very similar at both time points.