Socially connected brains

The overarching goal of the present research is to gain a better understanding of mechanisms that shape our interpersonal ties and social networks by investigating their associated brain bases in naturally occurring groups. All three studies rely on a novel round-robin neuroimaging paradigm that incorporates group members as both participants in the fMRI scanner (perceivers) and stimuli (targets) presented during a naturalistic face-viewing task. Study 1 elucidates how group members’ popularity is tracked by neural systems underlying valuation (i.e., processing reward value and evaluating others’ motivational significance), which in turn engage social cognition systems that facilitate understanding others’ mental states. Individual differences in the sensitivity of this neural mechanism are examined and found to correlate with perceivers’ own popularity. Studies 2 and 3 extend the paradigm developed in Study 1 to incorporate social network data collected in a longitudinal context, and further test whether neural measures collected during the initial stages of group formation can prospectively predict group members’ future liking ties (Study 2) and social network centrality (Study 3). In Study 2, neural activity in the aforementioned valuation systems predicts newly acquainted group members’ future—but not current—idiosyncratic liking of one another. Further analyses suggest this effect reflects only one facet of a far more nuanced interpersonal phenomenon implicated in the eventual emergence of dyadic liking reciprocity: individuals’ initial liking preferences are not personally tracked by their own brains’ idiosyncratic valuation responses to particular group members, but rather interpersonally tracked by the neural valuation responses they uniquely evoke in those particular group members; moreover, each dyad member’s idiosyncratic valuation activity influences both their own and each other’s future liking. Having established in Studies 1 and 2 a paradigm for measuring how social network members implicitly evaluate one another, Study 3 extends it to include oneself (i.e., the perceiver) as an evaluate target of social perception. Revisiting the Study 1 social network members’ data, enhanced valuation activity in response to oneself (relative to others) correlates positively with questionnaire measures of dispositional narcissism (but not self-esteem) and negatively with sociometric popularity. Using the data from Study 2, the trait narcissism effect is replicated and extended to a context in which the “others” are newly acquainted group members. This longitudinal data also reveals that the neural measure of narcissistic self-valuation prospectively predicts future (un)popularity, even controlling for initial levels of popularity. Considered together, this research aims to integrate conceptual and methodological frameworks across social psychology (e.g., round-robin experimental designs), cognitive neuroscience (e.g., fMRI), and sociology (e.g., social network analysis).