PreschoolersÕ effortful control and negative emotionality, immediate reactions to disappointment, and quality of social functioning Jeffrey Liew * , Nancy Eisenberg, Mark Reiser Department of Psychology, Arizona State University, Tempe, AZ 85287, USA Received 20 December 2003; revised 29 June 2004 Available online 23 August 2004 Abstract Relations among effortful control/low negative emotionality, immediate reactions in a sit- uation that usually calls for the masking of disappointment (i.e., the use of display rules), and social competence/adjustment were investigated for 78 preschool children (mean age = 4.87 years). Parents, teachers, and peers rated children on negative emotionality and/or effortful control as well as on social competence/adjustment. Children who were rated by parents and teachers as high on effortful control/low on negative emotionality expressed fewer imme- diate verbal/gestural indicators of disappointment in the presence of an unfamiliar adult and were perceived by their parents, teachers, and peers as socially competent and well adjusted. The pattern of findings was consistent with the view that childrenÕs immediate verbal/gestural reactions to disappointment partially mediated the relations between effortful control (as reported by parents) and social competence/adjustment. Ó 2004 Elsevier Inc. All rights reserved. Keywords: Effortful control; Self-regulation; Social competence; Adjustment; Temperament; Social cognition 0022-0965/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.jecp.2004.06.004 * Corresponding author. Fax: 1 480 965 8544. E-mail address: Jeffrey.Liew@asu.edu (J. Liew). J. Experimental Child Psychology 89 (2004) 298–319 www.elsevier.com/locate/jecp