William Fabricius is an associate professor in the Department of Psychology at Arizona State University. 

One of Fabricius' areas of research is children’s social cognitive development, in particular the development of children’s “theory of mind”. The topics he studies include young children’s early linguistic references to mental states, preschoolers’ reasoning about knowledge and belief and how that relates to their social behavior, and school-age children’s and high schoolers’ understanding of the interpretative nature of mental processes and how that relates to their understanding of conflict and their aggressive behavior.

Another area of research is father-child relationships, especially in divorced families. Fabricius is interested in the impact of these relationships on children’s health and well–being, and in the implications this research can have for social policy. Part of this work is in the context of a funded longitudinal study of fathers and stepfathers, and includes both quantitative and qualitative methods such as narrative analysis.