Attachment theory offers a novel developmental framework for understanding conversion reactions as having phylogenetic roots in two different innate animal defense behaviours: The 'freeze response' and 'appeasement defense behaviours'. From this perspective, conversion symptoms reflect two distinct, threat-elicited emotional responses, which are primed in context-dependent developmental experiences (pathways) and underpinned by different neurobiological mechanisms. The first of these two developmental pathways to conversion disorder involves the organization of self-protective strategies that incorporate components of the freeze response and involve inhibition of negative affective states in the context of punishment by caregivers. The second of these pathways involves the organization of self-protective strategies that incorporate innate appeasement defense behaviours in the context of unpredictable parental behaviours that threaten children's physical safety or emotional health. Seen from this developmental perspective, children with conversion disorders are not a homogenous group but fall into two distinct functional groups requiring different types of treatment.