Individual Differences in Infants’ Joint Attention Behaviors With Mother and a New Social Partner Elizabeth Meins, Charles Fernyhough, Bronia Arnott, Lucia Vittorini, and Michelle Turner Department of Psychology and Wolfson Research Institute Durham University Susan R. Leekam School of Psychology Cardiff University Kathryn Parkinson Institute of Health and Society Newcastle University Relations between infant–mother attachment security at 15 months and infants’ (N = 206) joint attention behaviors (a) with an experimenter at 8 and 15 months, and (b) with their mothers at 15 months were investigated. No concurrent or longitudinal relations were observed between attachment secu- rity and infants’ tendency to respond to an experimenter’s bids for joint atten- tion. Higher levels of initiating joint attention with an experimenter at 15 months were associated with insecure-avoidant attachment. Insecure- avoidant attachment was also associated with lower scores for initiating high-level joint attention behaviors (pointing, showing, and giving) with the mother at age 15 months. The fact that security-related differences in initiating joint attention with an experimenter were observed only once the attachment relationship was consolidated suggests that (a) attachment security may Correspondence should be sent to Elizabeth Meins, Department of Psychology, Science Laboratories, South Road, Durham DH1 3LE, UK. E-mail: elizabeth.meins@durham.ac.uk Infancy, 1–24, 2011 Copyright Ó International Society on Infant Studies (ISIS) ISSN: 1525-0008 print / 1532-7078 online DOI: 10.1111/j.1532-7078.2010.00065.x