What are quantitative traits? Quantitative, or complex, traits are traits for which phenotypic variation is continuously distributed in natural populations, with population variation often approximating a statistical normal distribution on an appropriate scale. Quantitative traits include aspects of morphology (height, weight); physiology (blood pressure); behavior (aggression); as well as mole...

Despite recent discoveries of genetic variants associated with autoimmunity and infection, genetic control of the human immune system during homeostasis is poorly understood. We undertook a comprehensive immunophenotyping approach, analyzing 78,000 immune traits in 669 female twins. From the top 151 heritable traits (up to 96% heritable), we used replicated GWAS to obtain 297 SNP associations a...

This study examined the extent to which positive and negative parenting relates to conduct problems (CP) and callous-unemotional (CU) traits among 172 adolescents (72 % males; Mage = 16.91 years, SD = .67) with attention-deficit/hyperactivity disorder and whether CU traits moderate the link between parenting and CP. Mothers reported on their adolescents' CP, CU traits, and their own parenting p...

Previous research on the Dark Triad traits (i.e., Machiavellianism, psychopathy, and narcissism) has focused solely on the role the Dark Triad traits played in mate choice of actors. The current study (N = 336) extends this by manipulating the apparent levels of Dark Triad traits in targets and correlating mate choice in these targets with individual differences in the Dark Triad traits in acto...

Statistical associations between phenotypic traits often result from shared developmental processes and include both covariation between the trait values and more complex associations between higher moments of the joint distribution of traits. In this article, an analytical technique for calculating the covariance between traits is presented on the basis of (1). the distribution of underlying g...

The purpose of this study is to investigate the dyadic associations between subclinical primary and secondary psychopathic traits and romantic attachment dimensions (avoidance and anxiety) in a sample of 140 couples from the community. Both partners completed self-report measures of psychopathic traits and romantic attachment. Actor–partner interdependence model analyses showed an actor effect ...

The liver is the central metabolic organ and exhibits fundamental functions in haematological traits. Hepatic expression, haematological, plasma biochemical, and body composition traits were assessed in a porcine model (n = 297) to establish tissue-specific genetic variations that influence the function of immune-metabolism-correlated expression networks. At FDR (false discovery rate) <1%, more...