A Quantitative Trait Locus Associated With Cognitive Ability in Children

Quantitative trait loci (QTLs) associated with general cognitive ability ( g ) were investigated for several groups of children selected for very high or for average cognitive functioning. A DNA marker in the gene for insulin-like growth factor-2 receptor (IGF2R) on Chromosome 6 yielded a significantly greater frequency of a particular form of the gene (allele) in a high- g group (.303; average IQ = 136, N = 51) than in a control group (.156; average IQ = 103, N = 51). This association was replicated in an extremely-high- g group (all estimated IQs > 160, N = 52) as compared with an independent control group (average IQ = 101, N = 50), with allelic frequencies of .340 and .169, respectively. Moreover, a high-mathematics-ability group ( N = 62) and a high-verbal-ability group ( N = 51) yielded results that were in the same direction but only marginally significant ( p = .06 and .08, respectively).     

Weigh(t)ing for Awareness

We wished to learn if weight perception can be extinguished by studying two patients with right hemisphere brain damage. When lifting weights simultaneously, a patient with right frontal damage was not biased in her judgments of which weight was heavier. By contrast, a patient with right parietal damage reported left-sided weights as being lighter than those on the right. Psychophysical power functions revealed that her awareness of increasing weights on the left was dampened compared to the right when lifting weights individually on each side. Strikingly, her awareness of weight changes on the left was completely abolished when she lifted weights in both hands simultaneously. She demonstrated an unusual split in awareness, being motorically aware of and actively engaged with left-sided weights while being unaware of their incremental changes.     

INCREASING RURAL HEAD START CHILDREN'S CONSUMPTION OF MIDDLE-CLASS MEALS1

Rural black, economically impoverished Head Start children, whose normal diets were deficient in nutritional requirements, were not consuming the nutritional breakfasts of, to them, unfamiliar foods provided by the county school system. This study investigated a positive simple method to increase the amount of food consumed and thereby ensure proper nutrition. Teachers dispensed sugar-coated cereal and small candies paired with praise contingent on eating behaviors and rewarded children who finished the entire meal with additional treats and praise. Substantial increases were produced in the proportion of meals consumed and in the number of children observed engaged in eating behaviors. These simple traditional behavioral procedures are readily available for any staff working with economically impoverished children as one method of increasing their sampling and consumption of unfamiliar nutritious foods.     

A sufficient condition for conditional expectation to be monotonically related to distribution parameters

In this paper we give a sufficient condition for conditional expectation to be a monotonic function of a parameter of the joint probability distribution. A second sufficient condition is given for the case where varying the parameter of the joint distribution leaves the shape of that distribution unchanged. Finally, an application of the condition is illustrated on the counter models for choice reaction time of LaBerge (1962) and Nickerson (1969).