Table 3. Multilevel Model of Linear and Quadratic Growth in RSA for Mothers and Children.

	Mothers		Children
	Coefficient	SE	Coefficient	SE
Intercept, π0
Intercept, β00	0.972	0.742	-0.637	0.698
Group, β01	-0.050	0.234	0.142	0.218
Average Synchrony, β02	-1.101	0.397*	0.245	0.379
Task RSA Average, β03	1.064	0.164***	1.129	0.141***
Baseline RSA Average, β03	-1.092	0.157***	-1.031	0.126***
Linear Growth, π1
Linear slope, β10	-0.448	0.324	0.234	0.315
Linear × Group, β11	-0.001	0.068	-0.048	0.057
Linear × Synchrony, β12	0.458	0.175*	-0.159	0.098
Linear × Task RSA, β13	0.014	0.072	-0.009	0.172
Linear × Baseline RSA, β13	0.013	0.068	-0.020	0.065
Quadratic Growth, π2
Quadratic slope, β20	-0.018	0.015	-0.016	0.029
Quadratic × Group, β21	0.010	0.005	0.003	0.009
Quadratic × Synchrony, β22	-0.036	0.016*	0.017	0.016
Quadratic × Task RSA, β23	-0.004	0.007	-0.002	0.006
Quadratic × Baseline RSA, β23	0.001	0.006	0.004	0.005

^*p <.05;

^**p <.01;

^***p <.001