In recent years many theorists within the field of critical realism have highlighted the drive within modern mainstream economics towards mathematical modelling (Lawson 1997; Fleetwood 1999). Simultaneously, a group of French economics students have criticised the discipline, describing it as autistic and calling for a return to reality (Devine 2002). More recently, a theory has been advanced drawing in part on the work of critical realism to provide a psychological explanation of autism spectrum conditions on the cognitive level (Lawson 2003). This paper provides an overview of this most recent theory and draws on it to offer an explanation as to why there is a drive towards closed system methodology (in the form of mathematisation) in mainstream economics. The drive is argued to result from a male tendency towards closed system thinking and evidenced by research into autism spectrum conditions.