Table 1.

Impacts of the two experiments at different time points.

	Newborn program				HV program
	6m	7/9m	12m	18m	30–36m	36-42m
Parents’ beliefs on
Impact of parents’ inputs	0.82***	0.61***	0.61***	0.38***	1.46***	1.25***
	0.00	0.00	0.00	0.00	0.00	0.00
	385	284	375	323	69	68
Parents’ inputs
Interactions w/childa	0.13	0.27**	0.10	0.10	0.62*	0.44
	0.42	0.03	0.37	0.41	0.08	0.25
	363	341	374	322	61	60
Child outcomes
Interactions w/parenta	−0.05	0.23**	-0.13	0.13	0.50*	0.30
	0.62	0.05	0.26	0.33	0.08	0.33
	363	341	374	322	61	60
Vocabularya		0.09	0.11	−0.04		0.31*
		0.35	0.45	0.58		0.08
		319	369	319		61
Math skills						0.48*
						0.05
						66
Social–emotional skills					0.44**	0.45*
					0.02	0.06
					69	68

Differences between treatment and control group means are shown first for the two experiments at different time points. Below in italics are the multiplicity-adjusted p-values based on a two-sided Student’s t test. The adjustment procedure follows List, Shaikh and Xu (2019). Families of outcomes for the adjustment are described in the Supplementary Information, section 5. Below the p-values is the number of observations used in the regression. *For multiplicity-adjusted p-value < 0.1, **for multiplicity-adjusted p-value < 0.05, ***for multiplicity-adjusted p-value < 0.01.

^aSignals that the measurement tools used in the two experiments are different (see Supplementary Information, section 4). In the 7/9 months column, beliefs are measured at 7 months, and interactions are measured at 9 months.