Expressions of shyness and theory of mind in children: A psychophysiological study

This study examined relations among expressions of state shyness, Theory of Mind (ToM), and resting respiratory sinus arrhythmia (RSA) in 78 typically developing four-year-old children (M_age = 54.59 months; 41 females). Expressions of positive and non-positive state shyness were coded from direct observations during a self-presentation task, ToM was assessed with validated vignette tasks, and resting RSA data were collected while children watched an emotionally neutral video. We found that ToM was positively related to expressions of positive shyness and inversely related to expressions of non-positive shyness, replicating previous work. These relations were qualified by an interaction between resting RSA and expressions of positive shyness when analyzed with respect to ToM, such that children with higher resting RSA and more expressions of positive shyness exhibited the most sophisticated ToM. As such, early ToM development may be facilitated by a combination of behavioral regulatory expressions and parasympathetic control.