Subclinical variation in mental health shapes the dynamics of everyday behaviour

Everyday behaviour is comprised of myriad components that must be seamlessly coordinated for action to be effective. Individual differences, specifically variation in mental health symptoms, influence how this challenge is navigated, however their impact in naturalistic settings remains unclear. Adopting a dynamical systems perspective, here we examined whether subclinical variation in symptoms associated with social anxiety disorder (SAD) and autism spectrum disorder (ASD) modulate individual movement dynamics during an everyday activity – walking on a university campus. Participants (n = 93) completed two walking trials, the second of which included an additional distractor task that they were either told to ignore or attend to. Gait dynamics were captured unobtrusively and assessed at both local (i.e., moment-to-moment) and global (i.e., time invariant) levels. The results revealed that subclinical variation symptoms of ASD were associated with less stable local dynamics, independent of task context. Further, exploratory analyses suggested that instructions to ignore the distractor were associated with changes to local dynamics for symptoms of SAD, but global dynamics for symptoms of ASD. Taken together, these findings highlight how individual differences in psychological factors can shape the dynamics of everyday behaviour in context-dependent ways.