Revisiting shyness and sociability: a preliminary investigation of hormone-brain-behavior relations.

Alva Tang,Geoffrey B Hall,Jay Schulkin,Louisa Schmidt,Elliott A Beaton

doi:10.3389/fpsyg.2014.01430

Alva Tang, Geoffrey B Hall + Show 3 more

Open Access

https://doi.org/10.3389/fpsyg.2014.01430

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Abstract

Shyness and sociability are two fundamental personality dimensions that are conceptually and empirically orthogonal and are conserved across cultures, development, and phylogeny. However, we know relatively little regarding how shyness and sociability are represented and maintained in the brain. Here we examined neural responses to the processing of different types of social threat using event-related fMRI, the salivary cortisol awakening response (CAR), and sociability in young adults selected for high and low shyness. Shy adults who exhibited a relatively higher CAR displayed neural activity in putative brain regions involved in emotional conflict and awareness, and were more sociable. In contrast, shy adults who displayed a relatively lower CAR exhibited neural activity in putative brain regions linked to fear and withdrawal, and were unsociable. Results revealed no systematic brain responses to social threat processing that correlated with the CAR in non-shy adults. These preliminary results suggest that individual differences in waking morning cortisol levels may influence neural processes that facilitate either social approach or withdrawal among people who are shy. Findings are discussed in relation to their theoretical and clinical implications for moving beyond longstanding descriptive to explanatory models of shyness and sociability and for understanding individual differences in social behavior in general.

Highlights

DATA ANALYSIS Partial least squares (PLS) analysis To address which corticolimbic regions correlated most strongly with morning salivary cortisol change scores, we examined between group differences in brain-cortisol correlations for two types of threat processing by conducting a behavioral-partial least squares (PLS)
RELATIONS BETWEEN MORNING SALIVARY CORTISOL CHANGE AND BRAIN SCORES (PLS) AMONG SHY ADULTS The two group PLS with morning salivary cortisol change score as the behavioral measure during the two types of threat conditions identified one significant Latent Variables (LVs). This LV revealed reliable brain-cortisol correlations for both threat conditions only in the shy group, but not for either conditions in the non-shy group as indicated by the wide confidence intervals (CIs; Figure 1)
WHAT ARE THE LINKS AMONG HORMONE, BRAIN, AND SOCIAL BEHAVIOR? We found that shy individuals who displayed a relatively higher cortisol awakening response (CAR) and bilateral rostral anterior cingulate cortex (ACC) activation scored higher on sociability

Summary

Introduction

Over three decades ago, Cheek and Buss (1981) observed that some people are quiet and anxious in social situations for different reasons: some people are quiet and withdrawn because they are shy and have little need to affiliate with others (i.e., they are unsociable), whereas others are inhibited and anxious because they are shy and desire to affiliate with others (i.e., they are sociable). Cheek and Buss (1981) demonstrated that shyness and sociability were conceptually and empirically orthogonal and, contrary to popular belief, the two were not interchangeable. Cheek and Buss (1981) developed short self-report measures of shyness and sociability and selected individuals who were high and low on shyness and sociability and had them interact during an unfamiliar social situation. The authors found that compared to their peers varying on high and low shyness and sociability, shy-sociable young adults exhibited significantly more anxious behavior, which were thought to originate from an approach– avoidance conflict, a combination of feelings of inhibition and desire to interact. Utility of the Cheek and Buss (1981) measurement model in predicting differential risk for psychopathology has been demonstrated, with higher substance use and abuse among shy-sociable and higher depression and loneliness among shy-unsociable adolescents and young adults (for a review, see Schmidt and Buss, 2010)

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