Real-World Joint Action and the Autism Spectrum: Separating Social Coordination from Motor Clumsiness

Poster Presentation
Friday, May 3, 2019: 11:30 AM-1:30 PM
Room: 710 (Palais des congres de Montreal)
D. A. Trevisan1,2, J. T. Enns3, E. Birmingham2 and G. Iarocci4, (1)Child Study Center, Yale University School of Medicine, New Haven, CT, (2)Faculty of Education, Simon Fraser University, Burnaby, BC, Canada, (3)Psychology, University of British Columbia, Vancouver, BC, Canada, (4)Simon Fraser University, Burnaby, BC, Canada

“Joint action”—the ability to coordinate actions with others—is critical for achieving individual and interpersonal goals (Sebanz, 2006), and for our collective success as a species (Tomasello, 2009). Joint actions require accurate and rapid inferences about others’ thoughts, intentions, and feelings (Pesquita, Whitwell, & Enns, 2017); skills that are thought to be impaired in ASD (Baron-Cohen, 2005). To date, research has not investigated joint action abilities in ASD during real-world social interactions.


1) To determine if there are joint action differences in children with ASD relative to typically developing (TD) children.

2) To determine if joint action differences in ASD are due to motor clumsiness or differences in cooperation abilities.

3) To determine how joint action differences in ASD are manifested with respect to correlates with behavioral and clinical measures.


Participants were children with ASD (n = 26) and TD children (n = 31), 6-12 years old, matched on age and Full-scale IQ (ASD mean = 102.64, TD mean = 109.50). Parents completed continuous measures of ASD traits, alexithymia, and social competence (Table 1).

Participants moved tables through an S-Shaped maze of stationary tables (obstacles) in three different conditions: “Child-Only” (child moved table by him/herself), “Child-Child” (two children moved table together), and “Child-Adult” (child moved table with adult researcher).

Joint action was measured using an iPhone attached to each table installed with a customized App that quantified table movement in three dimensions (greater table movement indicated less coordination).

The table moves were video-recorded so that we could subsequently code behavioral indices of interpersonal synchrony—operationalized as the percentage of time participants stepped synchronously versus asynchronously.


Children with ASD exhibited less table movement than TD children in the child-only condition, but significantly more table movement than TD children in the child-child condition (all ps < .05). This pattern suggests the TD children benefitted more from the aid of a peer than the ASD children (we termed difference scores between child-only and child-child, “cooperation benefit”) (Figure 1).

The calculated cooperation benefit was associated with higher verbal IQ (r = .402), higher social competence (r = .290), fewer autistic traits (r = -.302) and less alexithymia (r = -.230) across groups.

Children with ASD spent a significantly lower percentage of time stepping synchronously with their peer during the child-child condition, t(50.35) = 2.894, p = .006, but this ASD disadvantage was not evident when moving the table with an adult researcher in the child-researcher condition, t(48) = 0.47, p = .934.


Children with ASD were less likely to step synchronously with their peer when moving tables collaboratively, and they benefited less than TD children from the aid of a peer in completing the table-moving tasks. This lower “cooperation benefit” was associated with lower intelligence and social skills and higher alexithymia and autistic traits. The data suggest that joint action is a highly adaptive social process that may be impaired in ASD and not simply explained by motor clumsiness.