No abstract

The relationship of various dimensions of temperament, measured by the Tridimensional Personality Questionnaire (TPQ), to polymorphisms of the D2 dopamine receptor (DRD2) and D4 dopamine receptor (DRD4) genes was determined in 119 healthy Caucasian boys who had not yet begun to consume alcohol and other drugs of abuse. Total Novelty Seeking score of the TPQ was significantly higher in boys having, in common, all three minor (A1, B1, and Intron 6 1) alleles of the DRD2 compared to boys without any of these alleles. Boys with the DRD4 7 repeat (7R) allele also had a significantly higher Novelty Seeking score than those without this allele. However, the greatest difference in Novelty Seeking score was found when boys having all three minor DRD2 alleles and the DRD4 7R allele were contrasted to those without any of these alleles. Neither the DRD2 nor the DRD4 polymorphisms differentiated total Harm Avoidance score. Whereas subjects having all three minor DRD2 alleles had a significantly higher Reward Dependence 2 (Persistence) score than subjects without any of these alleles, no significant difference in this personality score was found between subjects with and without the DRD4 7R allele. In conclusion, DRD2 and DRD4 polymorphisms individually associate with Novelty Seeking behavior. However, the combined DRD2 and DRD4 polymorphisms contribute more markedly to this behavior than when these two gene polymorphisms are individually considered.

No abstract

Research has shown that learning disabled (LD) children are likely to develop a maladaptive pattern of causal attributions. However, it is unclear whether LD children are more likely to differ from their peers in terms of a greater tendency to attribute their difficulties to insufficient ability or in terms of a greater tendency to blame external factors. The present study found that LD girls were significantly more likely than nondisabled girls to attribute their difficulties to insufficient ability, but they did not differ in their tendency to attribute their difficulties to external factors. In contrast, LD boys were significantly more likely than nondisabled boys to attribute their difficulties to external factors, but they did not differ from nondisabled boys in their tendency to attribute their difficulties to insufficient ability. The present study also examined the differential implications of these two attributional tendencies. Although the tendency to blame one's ability was negatively related to persistence on a reading task administered by a novel adult, the tendency to attribute one's difficulties to external factors did not show this negative relation.