Half of all lifetime mental health disorders emerge in childhood (Kessler et al., 2007) and continue to develop through developmental stages. The transition from childhood to adulthood is a stressful developmental period during which anxiety problems are the most common mental health disorders, with a lifetime prevalence ranging from 15% to 30% (Essau, Conradt, & Petermann, 2002; Merikangas et al., 2010). Unfortunately, despite the notable negative impact of anxiety disorders on functioning at the social, emotional, and academic level, and their huge socioeconomic costs, their etiology remains unclear (Beidel & Alfano, 2011). From the moment of a child's birth, their emotional and physiological responses will be influenced by their parents through dyadic interactions that occur thousands of times during their development (Patterson, Dishion, & Bank, 1984). Quality interactions have been shown to foster secure parent-child attachment and to contribute to a child's social, cognitive, and emotional development over the years (Harrist & Waugh, 2002; Saint-Georges et al., 2013). In contrast, poor interactions have been associated with the emergence of problematic child behaviors (e.g., Landy & Menna, 2001). Research into developmental and social psychology indicates that the presence of non-verbal synchrony in dyadic interactions is associated with higher quality relationships, conformity, and more