Child Temperament as a Mediator of Mother-Toddler Problem Solving* Mary Gauvain, University of California, Riverside and Beverly Fagot, University of Oregon and Oregon Social Learning Center Abstract This paper is concerned with the role of child temperament in regulating adult-child cognitive interaction. Two studies were conducted to investigate whether child tem- perament as rated by the mother at an earlier time relates to maternal guidance and partner involvement on a joint task at a later time. In Study 1, 26 2.5-year-old chil- dren and their mothers participated in joint problem solving followed by a child-only posttest involving related tasks. Children rated as having more difficult tempera- ments received more cognitive assistance and disapproval from their mothers, as well as greater involvement from them in more challenging aspects of the tasks. Temperament was not related to child involvement during the joint task nor to task performance during the interaction or on the posttest. In Study 2, another group of 26 2.5-year-old children and their mothers participated in joint problem solving using different tasks than in Study 1. Results from Study 2 replicate those of Study 1. Also, children rated as having more difficult temperaments performed more poorly on the individual posttest. Results support the suggestion that child temperament may mediate the cognitive opportunities that arise during parent-child collaboration and are discussed in relation to Vygotsky's notion of the zone of proximal develop- ment. Keywords: Mother-child interaction; temperament; problem solving; preschool cognition; zone of proximal development; child difficulty. This paper is concerned with the role of child temperament as a mediator of adult-child problem solving. A long-standing assumption in developmental psy- chology is that temperamental difficulty in infancy leads to increased risk for behavioral problems in childhood. Although the linkages between early difficulty and later behavioral problems are not clearly established (see Plomin & Dunn, 1986), one possible connection may be that parents' early perceptions of their * A report of Study 1 was presented at the annual meeting of the American Educational Research Association, Boston, 1990. The parents and children who participated in this research are thanked for their participation. We also thank Kate Kavanagh for her help in developing the code, Wanda Grant, Denise Ford, and Cherie O'Boyle for their assistance on the project, Margaret McKean for her help in manuscript and figure preparation, and anonymous reviewers for their comments. The study was supported by NIMH Postdoctoral Grant MN16955 to the first author and by NIMH Postdoctoral Grant MH37911 to the second author. Address correspondence to Mary Gauvain, Department of Psychology, University of California, Riverside, Riverside, CA 92521. © BiackweU Publishers Ltd. 1995. Published by Blaekwell Publishers, 108 Cowley Road. Oxford OX4 UF, UK and 238 Main Street, Cambridge, MA 02142, USA.