Table 1.

Descriptive statistics of demographics, family characteristics, and physiology split by classic reactivity versus other types of reactivity

			Reactivity during Still Face Calculation				Recovery during Reunion Calculation
	Total Sample (N = 60)		Classic Reactivity (N = 28)		Other (N = 32)		Delayed ‘Classic Reactivity’ (N = 22)		Other (N =34)
Dichotomous Variable	N	%	N	%	N	%	N	%	N	%
Child Sex female	29	48.3	18	64.2	12	37.5	10	45.4	17	50.0
Race/Ethnicity: Latinx	20	33.3	10	35.7	10	31.2	6	27.2	12	35.2
: Black/African American	15	25.0	8	28.5	7	21.8	5	22.7	10	29.4
: White	7	11.6	2	7.1	5	15.6	5	22.7	2	5.8
: Multiracial/other	18	30.0	8	28.6	10	31.2	7	31.8	11	32.3
Maternal Smoking during pregnancy	2	3.3	0	0	0	0	0	0	0	0
Breastfeeding exclusively at 6 months	26	43.0	10	35.7	14	43.7	9	40.9	11	32.3
Completed Both SFP	40	66.6	18	64.2	23	71.8	11	50.0	29	85.3
Assigned to Intervention	20	33.3	10	35.7	10	31.2	5	22.7	11	32.3
Continuous Variables	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Maternal Prenatal Perceived Stress	1.87	0.66	19.46	6.43	17.48	5.85	19.98	5.25	17.56	6.49
Maternal Prenatal Stressful Life Events Count	2.57	2.07	3.04	1.89	2.5	2.67	2.86	2.65	2.74	2.28
Maternal Concurrent Perceived Stress	1.51	0.70	1.46	0.75	1.63	0.63	1.68	0.68	1.45	0.70
Maternal Reported Household Income ($)	26,143	20,941	27,555	21,364	23,200	20,763	28,213	22,053	23,082	18,965
Maternal Pre-pregnancy BMI	30.95	4.94	30.39	4.08	30.99	5.88	30.39	4.98	31.09	5.27
Maternal Gestational Age (days)	276.47	10.2	277.76	6.45	275.21	11.65	277.95	9.81	276.21	7.19
Birth Weight (kg)	3.32	0.46	3.35	0.43	3.29	0.43	3.21	0.41	3.40	0.46
Weight-for-length Standardized Change	1.19	1.77	0.97	1.87	1.35	1.54	1.56	1.97	1.02	1.53
Still Face Reactivity PEP	−0.79	2.73	−3.95	2.96	0.68	2.55	0.159	3.09	−2.56	3.67
Still Face Reactivity RSA	−0.56	1.11	−1.46	1.15	−0.082	0.95	−0.55	1.35	−0.93	1.24
Recovery PEP	−0.83	2.55	−.044	2.50	−1.12	2.62	−2.94	2.35	0.52	1.69
Recovery RSA	−0.01	1.50	0.67	1.63	−0.55	1.14	−1.26	0.99	0.81	1.21