Table 1.

Mean differences between social interaction variables at Time 1 and Time 2.

	Relative Time Use Estimates % Intervals
	Time 1	Time 2
Social Interaction Variables (from SECSI)	Mean (SD) n = 30	Mean (SD) n = 30	t-tests
Parentese Speech-1:1	40.44 (18.42)	5.53 (12.03)	9.74∗∗∗
Parentese Speech-Group	18.51 (7.20)	7.39 (15.60)	3.51∗∗
Standard Speech-1:1	10.03 (7.49)	33.31 (23.91)	-5.01∗∗∗
Standard Speech-Group	18.80 (7.93)	33.41 (17.06)	-5.23∗∗∗

^∗∗p < 0.01 ^∗∗∗p < 0.001.

SECSI, Social Environment Coding of Sound Inventory.

Time 1 measures were collected in infancy and Time 2 measures were collected in childhood at 33 months of age.