Associations between resting brain activity and socioemotional skills across the first 2 years of life.

Identifying and quantifying early markers of socioemotional skills, particularly within the first few years of life, remains a challenge in developmental research. This study examines whether infant resting electroencephalography (theta, alpha, beta, gamma, as well as the theta-beta ratio) at 1 month of age prospectively predicts socioemotional behavioral problems at 12 and 24 months. Data from 185 sociodemographically diverse mother-infant dyads (53.51% female; 38.92% White; 44.32% Hispanic) were included in the analysis. Results indicated that whole-brain resting brain function at 1 month of age did not significantly predict socioemotional behavioral problems at 12 months of age; however, higher whole-brain relative theta and lower whole-brain relative alpha at 1 month significantly predicted more socioemotional behavioral problems by 24 months of age. Exploratory analyses examining regional brain activity are also presented. Together, these findings suggest that resting brain activity at 1 month of age may be an early indicator of later socioemotional behavioral problems in a diverse, nonclinical sample. (PsycInfo Database Record (c) 2026 APA, all rights reserved).