CoupleID	ID	Day	DCS	Husband	Wife	Person Mean	DCS_Self	DCS_Spouse
1	101	1	−1	1	0	−1.5	0.5	0
1	101	2	−2	1	0	−1.5	−0.5	−0.5
1	101	3	−2	1	0	−1.5	−0.5	0.5
1	101	4	−1	1	0	−1.5	0.5	0
1	102	1	−2	0	1	−2	0	0.5
1	102	2	−2.5	0	1	−2	−0.5	−0.5
1	102	3	−1.5	0	1	−2	0.5	−0.5
1	102	4	−2	0	1	−2	0	0.5

Note: DCS = Diurnal Cortisol Slope. DCS_Self = DCS - Person Mean. It represents deviation of the individual’s DCS on a particular day from the person mean. DCS_Spouse (denoted as SPOUSE_ti in Equation 1) is the spouse’s person-centered cortisol slope.

SAS Syntax for Multilevel Dyadic Synchrony Model (Equation 1):

PROC MIXED COVTEST METHOD=REML;
     CLASS CoupleID Day;
     MODEL DCS = Husband Wife DCS_Spouse / NOINT S DDFM=sat;
     RANDOM Husband Wife / TYPE=un SUB=CoupleID G GCORR;
     RANDOM DCS_Spouse / TYPE=un SUB=CoupleID G;
RUN;