The Magnitude of Genetic and Environmental Influences on Parental and Observational Measures of Behavioral Inhibition and Shyness in Toddlerhood

Abstract

Behavioral inhibition is a temperamental trait that refers to slow approach to novel items, shyness towards new people, and fearfulness in new situations, and individuals may develop inhibited response styles by as early as two years of age. There are important methodological considerations in the assessment of early temperament, with parental report and observational measures providing both corroborative and unique data. The present study examined behavioral inhibition measured by parental report and observational measures in a genetically informative sample to delineate the agreement between the methods and the uniqueness of each method, and to estimate the magnitude of genetic and environmental influences on the common and unique variance. The biometric, psychometric, and rater bias models were conducted to study the covariance between measurement modalities. Overall, the results suggested a common phenotype was assessed by both parents and observers. The latent phenotype underlying parental and observational measures of behavioral inhibition was moderately to substantially heritable.

An examination of the developmental propensity model of conduct problems.

“…Some of the CADS items are not developmentally appropriate for toddlers. Also, although there is evidence for the reliability and validity of the antisocial propensity measures examined here (Rhee et al, 2012; Rhee, Boeldt, et al, 2013; Smith et al, 2012), they were chosen post-hoc rather than developed specifically to test the developmental propensity model, as the CADS was. Moreover, it was not possible to examine whether the very early antisocial propensity dimensions examined here and the CADS dimensions assess the same constructs, as the CADS was not available in our study.…”

“…In the present study, antisocial propensity dimensions examined included negative emotionality, behavioral inhibition (a construct that may be inversely associated with daring), concern and disregard for others (constructs closely related to prosociality), general cognitive ability, and language ability. These dimensions were chosen given the similarity of the constructs available to those discussed in the original model, and because the reliability and validity of these assessments in toddlerhood were established in previous studies (Rhee et al, 2012; Rhee, Boeldt, et al, 2013; Smith et al, 2012). …”

Self-reported impulsivity, but not behavioral approach or inhibition, mediates the relationship between stress and self-control

“…Gender-related differences have been reported more consistently in research examining behavioral approach and inhibition, with women having higher levels of behavioral inhibition and reward responsiveness than men (Cross et al, 2011; Hamilton et al, 2012; Perry et al, 2013). Even when assessed as toddlers, girls were significantly more behaviorally inhibited than boys (Smith et al, 2012). Because there are gender-related differences in dimensions of behavioral approach and inhibition, any mediational effects of the constructs in the relationship of stress and self-control also may differ by gender.…”

Testing Alternative Hypotheses Regarding the Association Between Behavioral Inhibition and Language Development in Toddlerhood

“…The term behavioral inhibition is used in the present study as a general term to encompass the range of constructs associated with inhibited response styles, including shyness, inhibition, and fearfulness (e.g., Kagan et al, 1984; Robinson, Kagan, Reznick, & Corley, 1992), whereas shyness has been defined as a hesitation to be a part of social interactions, despite the desire to be included (e.g., Cameron, 2009), which is often motivated by anxiety around social evaluation (Rubin & Asendorpf, 1993), Although most previous research has focused on the association between shyness and language development, the behavioral inhibition construct was used in the present study because it reflects a more general temperamental construct that encompasses other traits that are highly correlated with shyness, and because results of a previous study suggest that inhibition to various novel situations (including social situations) are manifestations of the same latent construct (Smith et al, 2012). Additionally, the availability of ratings from distinct sources and contexts to create a broader behavioral inhibition construct reduces measurement error.…”