Using the Flanker Task to Examine Genetic and Environmental Contributions in Inhibitory Control Across the Preschool Period.

The limited research exploring genetic and environmental influences on inhibitory control (IC) in preschoolers has relied on parent ratings or simple delay tasks and has produced mixed results. The present study uses a cognitively-challenging Flanker task to examine genetic and environmental contributions to the development of early IC in a longitudinal sample of 310 same-sex twin pairs (123 MZ; 187 DZ; 51% female) assessed at ages 3, 4 and 5 years. IC was significantly heritable at each age (a2: age 3 = .36; age 4 = .36; age 5 = .35). Stability was entirely accounted for by genetic influences, and change was explained by genetic and nonshared environmental factors. No significant shared environmental influences were observed.

Personal socio-cultural preferences modulate neural correlates of decisions to socialize with powerful persons.

Social power differences fundamentally shape the behavioral interaction dynamics of groups and societies. While it has long been recognized that individual socio-cultural preferences mitigate social interactions involving persons of power, there is limited empirical data on the underlying neural correlates. To bridge this gap, we asked university student participants to decide whether they were willing to engage in social activities involving their teachers (higher power status), classmates (equal power status), or themselves (control) while functional brain images were acquired. Questionnaires assessed participants' preferences for power distance, uncertainty avoidance, and cultural intelligence. As expected, participants generally accepted more social interactions with classmates than teachers. Also, left inferior frontal activity was higher when accepting than when rejecting social interactions with teachers. Critically, power distance preferences further modulated right lateral frontoparietal activity contrasting approach relative to avoidance decisions towards teachers. In addition, uncertainty avoidance modulated activity in medial frontal, precuneus, and left supramarginal areas distinguishing approach decisions towards teachers relative to classmates. Cultural intelligence modulated neural responses to classmate approach/avoidance decisions in anterior cingulate and left parietal areas. Overall, functional activities in distinct brain networks reflected different personal socio-cultural preferences despite observed social decisions to interact with others of differential power status. Such findings highlight that social approach or avoidance behaviors towards powerful persons involves differential subjective neural processes possibly involved in computing implicit social utility.

Study Preregistration: Understanding the Etiology of Externalizing Problems in Young Children: The Roles of Callous-Unemotional Traits and Irritability.

Externalizing behavioral problems in young children are associated with later delinquency and crime,1 which can cause burdens at both personal and socialeconomic levels. The heterogeneity of externalizing problems emphasizes the importance of examining the etiological mechanisms that underlie externalizing problems and related behaviors. The present study focuses on 2 risk factors for externalizing behavioral problems in early childhood: callous-unemotional traits (CU), characterized as a lack of guilt and empathy,2 and irritability, a tendency to show anger and frustration.3 Behavioral genetic studies find that externalizing problems, CU, and irritability are heritable,4,5 raising the possibility of common genetic effects linking the 3 behaviors, but this has not been previously explored. Neurological evidence suggests distinct pathways from CU and irritability to externalizing problems,6 implying that the genetic and environmental factors linking externalizing problems and CU may differ from those linking externalizing problems and irritability. We predict that there will be common genetic influences operating across externalizing problems, CU, and irritability; but we also predict unique genetic and environmental influences representing distinctive risks shared between externalizing problems and CU, and between externalizing problems and irritability, respectively.

Influence of culture and age on the self-reference effect.

Relating information to oneself can enhance memory for young and older adults. However, most studies investigating self-referencing have focused on Western populations, for whom the self is considered an independent and distinct entity. Whether self-referencing as a mnemonic strategy similarly benefits East Asians, cultures associated with interdependent self-construal, has been investigated little, particularly with age. In this study, we investigated the effect of self-reference on memory for both younger and older adults from American and Taiwanese cultures, predicting that self-referencing would be a less effective strategy for younger and older adults from Taiwan compared to Americans. Results reveal some cultural differences with age, with Taiwanese older adults benefitting less from self-referencing than younger Taiwanese, though the effect did not differ with age for Americans, or between younger adults across cultures. Thus, our results suggest that the potential mnemonic benefits of self-referencing may be limited in older adults from Eastern cultures.