Positive shyness and frontal EEG alpha/delta ratio in children: A pilot study

In two separate recent studies, researchers have reported an association between increases in children's shyness (i.e., social avoidance and inhibition) and decreases on frontal baseline electroencephalogram (EEG) alpha-to-delta ratio (ADR) scores (i.e., Schmidt & Poole, 2018, 2020). Here we attempted to extend these findings by examining whether different types of children's shyness were distinguishable on this same frontal ADR score, which is thought to be one electrocortical proxy of brain maturation. We coded expressions of positive shyness (i.e., co-occurrence of smiling and avoidance behaviors) versus non-positive shyness (i.e., avoidance behaviors) from direct observations during a social presentation speech in children (N = 63; M age = 10.41 years) and examined these expressions of shyness in relation to the children's frontal baseline EEG ADR scores. We found preliminary evidence that children expressing positive shyness exhibited the lowest frontal baseline EEG ADR score (i.e., ostensibly less brain maturation) relative to children expressing non-positive shyness and low levels of shyness. We speculate that relatively less frontal brain maturation may be linked to some adaptive features of shyness.