Related Experiment Video
Updated: May 29, 2026

Functional Near-Infrared Spectroscopy Hyperscanning Study in Psychological Counseling
Published on: January 17, 2025
Newborn irritability moderates the association between infant attachment security and toddler exploration and
Brandi Stupica1, Laura J Sherman, Jude Cassidy
1Department of Psychology, University of Maryland, College Park, MD 20742, USA. bstupica@umd.edu
None:
This longitudinal investigation of 84 infants examined whether the effect of 12-month attachment on 18- and 24-month exploration and sociability with unfamiliar adults varied as a function of newborn irritability. As expected, results revealed an interaction between attachment (secure vs. insecure) and irritability (highly irritable vs. moderately irritable) in predicting both exploration and sociability with unfamiliar adults. For exploration, results supported a dual-risk model; that is, toddlers who had been both highly irritable and insecurely attached were less exploratory than other toddlers. For sociability, results supported the differential-susceptibility hypothesis; that is, highly irritable infants, compared to moderately irritable infants, were both less sociable as toddlers when they had been insecurely attached and more sociable when they had been securely attached.
Related Concept Videos
Attachment
Relationship with Parents: Attachment
Theory of Romantic Attachment in Adulthood
Socioemotional Development during Infancy
Primary Temperament Types
Stella Chess...
Piaget's Stage 1 of Cognitive Development
Exploration...
Hazan and Shaver's Attachment Styles

