Vagal tone is widely believed to be an important physiological aspect of emotion regulation and associated positive behaviors. However, there is inconsistent evidence for relations between children’s baseline vagal tone and their helpful or prosocial responses to others (Hastings & Miller, 2014). Recent work in adults suggests a quadratic association (inverted U-shape curve) between baseline vagal tone and prosociality (Kogan et al., 2014). The present research examined whether this nonlinear association was evident in children. We found consistent evidence for a quadratic relation between vagal tone and prosociality across 3 samples of children using 6 different measures. Compared to low and high vagal tone, moderate vagal tone in early childhood concurrently predicted greater self-reported prosociality (Study 1), observed empathic concern in response to the distress of others and greater generosity toward less fortunate peers (Study 2), and longitudinally predicted greater self-, mother-, and teacher-reported prosociality 5.5 years later in middle childhood (Study 3). Taken together, our findings suggest that moderate vagal tone at rest represents a physiological preparedness or tendency to engage in different forms of prosociality across different contexts. Early moderate vagal tone may reflect an optimal balance of regulation and arousal that helps prepare children to sympathize, comfort, and share with others.

Physiological synchrony within a dyad, or the degree of temporal correspondence between two individuals' physiological systems, has become a focal area of psychological research. Multiple methods have been used for measuring and modeling physiological synchrony. Each method extracts and analyzes different types of physiological synchrony, where 'type' refers to a specific manner through which two different physiological signals may correlate. Yet, to our knowledge, there is no documentation of the different methods, how each method corresponds to a specific type of synchrony, and the statistical assumptions embedded within each method. Hence, this article outlines several approaches for measuring and modeling physiological synchrony, connects each type of synchrony to a specific method, and identifies the assumptions that need to be satisfied for each method to appropriately extract each type of synchrony. Furthermore, this article demonstrates how to test for between-dyad differences of synchrony via inclusion of dyad-level (i.e., time-invariant) covariates. Finally, we complement each method with an empirical demonstration, as well as online supplemental material that contains Mplus code.

No abstract

The links among mothers’ compassionate love for their child, autonomic nervous system activity, and parenting behavior during less and more challenging mother–child interactions were examined. Mothers expressed and reported less negative affect when they exhibited autonomic patterns of increased parasympathetic dominance (high parasympathetic and low sympathetic activation) or autonomic coactivation (high parasympathetic and high sympathetic activation) during the less challenging interaction and autonomic coactivation during the more challenging interaction. Compassionate love predicted less reported and observed negativity in mothers who showed increased sympathetic nervous system dominance (high sympathetic and low parasympathetic activation). Compassionate love appeared to help mothers, and particularly those who experienced strong physiological arousal during difficult parenting situations, establish positive socialization contexts for their children and avoid stress-induced adverse parenting.

Altruism, although costly, may promote well-being for those who give. Costly giving by adults has received considerable attention, but less is known about the possible benefits, as well as biological and environmental correlates, of altruism in early childhood. In the current study, we present evidence that children who forgo self-gain to help others show greater vagal flexibility and higher subsequent vagal tone than those who do not, and children from less wealthy families behave more altruistically than those from wealthier families. These results suggest that altruism should be viewed through a biopsychosocial lens; that privileged contexts have an early-emerging influence on children's willingness to make personal sacrifices for others; and that altruism and healthy vagal functioning may share reciprocal relations in childhood. When children help others at a cost to themselves, they could be playing an active role in promoting their own well-being as well as the well-being of others.