Understanding allostasis: Early‐life self‐regulation involves both up‐ and down‐regulation of arousal.

Optimal performance lies at intermediate autonomic arousal, but no previous research has examined whether the emergence of endogenous control associates with changes in children's up‐regulation from hypo‐arousal, as well as down‐regulation from hyper‐arousal. We used wearables to take day‐long recordings from N = 58, 12‐month‐olds (60% white/58% female); and, in the same infants, we measured self‐regulation in the lab with a still‐face paradigm. Overall, our findings suggest that infants who showed more self‐regulatory behaviors in the lab were more likely to actively change their behaviors in home settings moment‐by‐moment "on the fly" following changes in autonomic arousal, and that these changes result in up‐ as well as down‐regulation. Implications for the role of atypical self‐regulation in later psychopathology are discussed. [ABSTRACT FROM AUTHOR]