“…The relational complexity metric has been applied to tasks in many different content domains including transitive inference (Halford, 1984 ; Andrews and Halford, 1998 ; Andrews, 2010 ; Andrews and Mihelic, 2014 ), suppositional reasoning (Birney and Halford, 2002 ), categorical syllogisms (Zielinski et al, 2010 ), conditional reasoning (Cocchi et al, 2014 ), class inclusion (Halford and Leitch, 1989 ), inferences based on classification hierarchies (Halford et al, 2002b ), card sorting (Halford et al, 2007a ), balance scale reasoning (Halford et al, 2002a ; Andrews et al, 2009 ), numerical reasoning (English and Halford, 1995 ; Andrews and Halford, 2002 ; Knox et al, 2010 ), and theory of mind (Andrews et al, 2003 ; Halford and Andrews, 2014 ), as well as decision making in gambling tasks (Bunch et al, 2007 ; Andrews et al, 2008 ), delay of gratification (Bunch and Andrews, 2012 ), reversal learning and conditional discrimination (Andrews et al, 2012 ), and comprehension of relative clause sentence (Andrews et al, 2006 ). The breadth with which the relational complexity metric has been (can be) applied contrasts with other metrics that apply to specific content domains or tasks with a specific structure.…”