Jared Lessard

Sex Modulates the Associations Between the COMT Gene and Personality Traits

Previous research has shown inconsistent findings regarding the relations between the functional Val158Met polymorphisms of the catechol-O-methyltransferase (COMT) gene and individual differences in personality traits. This study attempts to overcome some of the weaknesses of previous research, namely, small sample sizes, clinical samples, ethnic stratification, wide age ranges, neglecting sex differences, and single measures of personality traits. A large sample (n=556, 250 male, 306 female) of healthy Chinese college students (mean age=20.5±1 years) was given a battery of personality scales, including the temperament and character inventory-revised, the behavioral inhibition system and behavioral approach system scale, the Beck depression inventory, and the Beck anxiety inventory. Factor analysis of the affect-related personality traits revealed two factors that corresponded to positive (PEM) and negative emotionality (NEM). We found a consistent COMT-by-sex interaction effect on affect-related personality traits. Compared with males with Met/Met alleles, males with Val/Val alleles showed significantly higher scores on NEM, but lower scores on PEM. Females, however, showed an opposite but nonsignificant pattern. Our results supported the role of the COMT gene in personality traits for males and contributed to the growing literature on sex differences in gene–behavior connections.

Are youths' feelings of entitlement always "bad"?: Evidence for a distinction between exploitive and non-exploitive dimensions of entitlement

Previous personality research (e.g., Campbell et al., 2004) has described the sense of entitlement as an unifactorial construct. In this study, we examined characteristics of two potential facets of entitlement: exploitive entitlement, characterized by exploitive interactions and expectations of special treatment, and non-exploitive entitlement, or entitled beliefs that rest on notions of self-worth and fairness. 466 college students (mean age = 20.5) completed a questionnaire consisting of unifactorial and two-factor measures of entitlement and other personality dispositions and attitudes. As expected, both exploitive and non-exploitive entitlement were positively related to the Psychological Entitlement Scale (PES; r = .51 and r = .43, respectively), an unifactorial measure of entitlement. In other respects, exploitive and non-exploitive entitlement had quite distinct correlates. Exploitive entitlement was uniquely related to higher levels of psychopathy and neuroticism, and lower levels of work orientation, social commitment, and self-esteem; whereas non-exploitive entitlement was uniquely associated with higher self-esteem.

Genetic variations in the dopaminergic system and alcohol use: a system‐level analysis

Alcohol use is highly heritable and has been associated with many gene variants, including those related to dopamine (DA). However, single gene association studies have shown inconsistent and small effects. Using a system‐level approach, the current study aimed to estimate the overall effect of genetic variations in the DA system on alcohol use among male drinkers. One hundred seventy‐six male college students who reported to have ever drunk alcohol were enrolled. Alcohol use was measured using the Alcohol Use Disorders Identification Test. Ninety‐eight representative polymorphisms in all major DA neurotransmitter genes were genotyped. Using analysis of variance, we identified six single‐nucleotide polymorphisms (SNP)s that made statistically significant contributions to alcohol use. Next, main effects and interactions of these SNPs were assessed using multiple regression. The final model accounted for approximately 20% of the variance for alcohol use. Finally, permutation analyses ascertained the probability of obtaining these findings by chance to be low, p ranging from 0.024 to 0.048. These results confirmed that DA‐related gene variants made strong contributions to reported alcohol use and suggest that multiple regression can be a promising way to explore the genetic basis for multi‐gene‐determined human behaviors.

Genetic variations in the dopamine system and facial expression recognition in healthy chinese college students.

Objective: This study investigated the relation between genetic variations in the dopamine system and facial expression recognition. Methods: A sample of Chinese college students (n = 478) was given a facial expression recognition task. Subjects were genotyped for 98 loci [96 single-nucleotide polymorphisms (SNPs) and 2 variable number tandem repeats] in 16 genes involved in the dopamine neurotransmitter system, including its 4 subsystems: synthesis (TH, DDC, and DBH), degradation/transport (COMT,MAOA,MAOB, and SLC6A3), receptors (DRD1,DRD2,DRD3,DRD4, and DRD5), and modulation (NTS,NTSR1,NTSR2, and NLN). To quantify the total contributions of the dopamine system to emotion recognition, we used a series of multiple regression models. Permutation analyses were performed to assess the posterior probabilities of obtaining such results. Results: Among the 78 loci that were included in the final analyses (after excluding 12 SNPs that were in high linkage disequilibrium and 8 that were not in Hardy-Weinberg equilibrium), 1 (for fear), 3 (for sadness), 5 (for anger), 13 (for surprise), and 15 (for disgust) loci exhibited main effects on the recognition of facial expressions. Genetic variations in the dopamine system accounted for 3% for fear, 6% for sadness, 7% for anger, 10% for surprise, and 18% for disgust, with the latter surviving a stringent permutation test. Conclusions: Genetic variations in the dopamine system (especially the dopamine synthesis and modulation subsystems) made significant contributions to individual differences in the recognition of disgust faces.

Neural systems for reflected and direct self-appraisals in Chinese young adults: Exploring the role of the temporal-parietal junction.

Objectives: Although cortical midline structures (CMS) are the most commonly identified neural foundations of self-appraisals, research is beginning to implicate the temporal-parietal junction (TPJ) in more interdependent self-construals. The goal of this study was to extend this research in an understudied population by (a) examining both direct (first-person) and reflected (third-person) self-appraisals across 2 domains (social and academics), and (b) exploring individual differences in recruitment of the TPJ during reflected self-appraisals. Method: The neural correlates of direct and reflected self-appraisals in social and academic domains were examined in 16 Chinese young adults (8 males, 8 females; aged 18–23 years) using functional MRI. Results: As expected, when making reflected self-appraisals (i.e., reporting what they believed others thought about them, regardless of domain), Chinese participants recruited both CMSs and the TPJ. Similar to previous research in East Asian and interdependent samples, CMSs and the TPJ were relatively more active during direct self-appraisals in the social than in the academic domain. We additionally found that, to the extent participants reported that reflected academic self-appraisals differed from direct academic self-appraisals, they demonstrated greater engagement of the TPJ during reflected academic self-appraisals. Exploratory cross-national comparisons with previously published data from American participants revealed that Chinese young adults engaged the TPJ relatively more during reflected self-appraisals made from peer perspectives. Conclusions: In combination with previous research, these findings increase support for a role of the TPJ in self-appraisal processes, particularly when Chinese young adults consider peer perspectives. The possible functional contributions provided by the TPJ are explored and discussed.

Etiology of Teen Dating Violence among Adolescent Children of Alcoholics

Family processes in early life have been implicated in adolescent involvement in teen dating violence, yet the developmental pathways through which this occurs are not well understood. In this study, etiological pathways from parental psychopathology and marital conflict in infancy to involvement in dating violence in late adolescence were examined in a sample of children at high-risk due to parental alcohol problems. Families (N = 227) recruited when the child was 12 months of age were assessed at 12-, 24-, 36-months, kindergarten, 6th, 8th, and 12th grades. Slightly more than half of the children were female (51%) and the majority were of European American descent (91%). Parental psychopathology in infancy was indirectly associated with teen dating violence in late adolescence via low maternal warmth and self-regulation in early childhood, externalizing behavior from kindergarten to early adolescence, and sibling problems in middle childhood. Marital conflict was also indirectly associated with teen dating violence via child externalizing behavior. Maternal warmth and sensitivity in early childhood emerged as an important protective factor and was associated with reduced marital conflict and increased child self-regulation in the preschool years as well as increased parental monitoring in middle childhood and early adolescence. Family processes occurring in the preschool years and in middle childhood appear to be critical periods for creating conditions that contribute to dating violence risk in late adolescence. These findings underscore the need for early intervention and prevention with at-risk families.

Physiological reactivity during object manipulation among cigarette-exposed infants at 9 months of age☆

The purpose of this study was to examine the association between prenatal exposure to cigarettes and heart rate during an object manipulation task at 9 months of age. Second-by-second heart rate was recorded for 181 infants who were prenatally exposed to cigarettes and 77 nonexposed infants during the manipulation of four standardized toys. A series of longitudinal multilevel models were run to examine the association of prenatal smoking on the intercept and slope of heart rate during four 90-second object manipulation tasks. After controlling for maternal age, prenatal marijuana and alcohol use, duration of focused attention and activity level, results indicated that the heart rates of exposed infants significantly increased during the object manipulation task. These findings suggest casual rather than focused attention and a possible increase in physiological arousal during object manipulation.