Journal of Autism and Developmental Disorders, VoL 24, No. 5, 1994 A Second Look at Second-Order Belief Attribution in Autism 1 Helen Tager-Flusberg 2 and Kate Sullivan University of Massachusetts at Boston Compared the performance of autistic and mentally retarded subjects, all of whom had passed a standard first-order test of false belief, on a new second-order belief tasic 12 autistic and 12 mentally retarded subjects, matched on verbal mental age (assessed by PPI/T and a sentence comprehension subtest of the CELF) and full-scale IQ were given two trials of a second-order reasoning task which was significantly shorter and less complex than the standard task used in all previous research. The majority of subjects in both groups passed the new task, and were able to give appropriate justifications to their responses. No group differences were found in performance on the control or test questions. Findings are interpreted as evidence for the roleof information processing factors rather than conceptual factors in performance on higher order theory of mind tasks. Current studies of theory of mind abilities in autism have focused primarily on attributions of first-order mental states, especially false beliefs (e.g., Baron-Cohen, Leslie, & Frith, 1985; Dawson & Fernald, 1987; Leslie & Frith, 1988; Oswald & Ollendick, 1989; Perner, Frith, Leslie, & Leekam, 1989; Prior, Dahlstrom, & Squires, 1990; Reed & Paterson, 1990). The ability tThis study was supported by a grant from the National Institute of Deafness and Other Communication Disorders (1RO1 DC 01234). We thank Jason Barker for his extensive help with this study. We are also very grateful to the schools where the study was conducted including the League School, and the public school systems in the following towns in Massachusetts: Hanover, Hanson, Hingham, Milton, Plymouth, and RocHand. We offer special thanks to Alan Dewey, Mary Dollar, Sandy D'Giacomo, Herman Fishbein, William Griffin, Nancy Kearns, Judy Monahan, Debbie Newhall, Cay Riley, Robert Sherman, and Kathy Staska for their continued support of our research. 2Address all correspondence to Helen Tager-Flusberg, Department of Psychology, University of Massachusetts, 100 Morrissey Boulevard, Boston, Massachusetts 02125. 577 0162-3257/9.4/1000-.0577507.00/0 ,~ 1994 Plenum Publishing Corporation