Frontal Asymmetry in Infancy: Predictive Utility for Distinct Patterns of Temperament

ABSTRACT Recent theorising has emphasised motivational systems, rather than specific emotional reactions, when interpreting frontal asymmetry. We examined the predictive utility of infant electroencephalogram (EEG) frontal asymmetry during two approach‐oriented tasks within 82 mother‐infant dyads (infant age: M = 38.88 weeks, SD = 8.13 weeks; infant ethnicity: 86.7% Caucasian; infant sex: 51.2% female). Peek‐a‐boo (PAB) and toy removal (TR) were chosen as predictors of mother‐reported temperament, as both elicit approach motivation via a blocked goal in a joyful and frustrating context, respectively. TR asymmetry effect on surgency/positive affectivity (SPA) was observed and driven primarily by a significant predictive relationship between TR asymmetry and smiling and laughter, f 2 = 0.31. Negative emotionality (NE) related outcomes were predicted by TR asymmetry, driven by sadness, f 2 = 0.20. Other than occasional contributions of covariates, no additional statistically significant results were noted. These findings are discussed as most consistent with the capability model of lateralization.