This study examined individual differences in affective attention trajectories in infancy and relations with competence and social reticence at 24 months. Data collection spanned 2017 to 2021. Infants (N = 297, 53% White, 49% reported as assigned male at birth) recruited in South Central and Central Pennsylvania and Northern New Jersey provided eye-tracking data at five assessments. Caregivers self-reported anxiety symptoms, infant temperamental negative affect, and infant competence at the final assessment. A subgroup of infants participated in a peer social dyad at the final assessment. Using group-based trajectory modeling, we found three groups of infants with different affective attention trajectories: affective attention increasers (n = 73), affective attention shifters (n = 156), and affective attention decreasers (n = 50). Affective attention increasers exhibited low intercepts with steep attention increases, particularly to angry facial configurations. Affective attention shifters exhibited middle intercepts with attention decreases to facial configurations but an attention increase to angry facial configurations. Affective attention decreasers exhibited high intercepts with steep attention decreases. Infants in the affective attention increasers group exhibited more competence when accounting for caregiver anxiety symptoms and infant temperamental negative affect. Group membership was not related to social reticence during the peer social dyad. Infants higher in temperamental negative affect exhibited more social reticence, particularly as the social dyad continued. Our results provide evidence for individual differences in developmental trajectories of affective attention and relations with toddler social behavior. Our results are primarily generalizable to rural and urban populations in the Midatlantic United States. (PsycInfo Database Record (c) 2024 APA, all rights reserved).