Table 2.

Covariate analysis summary

	SES × age group (n = 304)				SES × age group controlling for childhood SES (n = 168)
	Brain system segregation		Cortical thickness		Brain system segregation		Cortical thickness
Covariates	F	P	F	P	F	P	F	P
Head motion only	3.16	0.025*	2.67	0.048*	2.85	0.039*	0.65	NS
Demographic + head motion	2.47	0.062+	2.81	0.040*	2.79	0.042*	0.97	NS
Physical health + head motion	3.11	0.027*	2.26	0.082+	2.58	0.056+	0.78	NS
Mental health + head motion	3.15	0.026*	2.81	0.040*	2.59	0.055+	1.22	NS
Fluid intelligence + head motion	2.97	0.032*	2.23	0.085+	2.73	0.046*	0.56	NS
Long-term episodic memory + head motion	3.41	0.018*	2.67	0.048*	2.98	0.033*	0.68	NS

Summary of SES by age group interactions on brain system segregation and mean cortical thickness: controlling for multiple sets of covariates (left), controlling for covariates and childhood SES in a subsample of participants who had childhood-SES information available (right). Head motion refers to estimated measures of participants’ in-scanner head motion (mean FD); demographic variables include sex and race; physical health variables include BMI, SF-36 PCS, hypertension, smoker status, alcohol consumption, and chronic health issues; mental health variables include depressive symptoms and life satisfaction; fluid intelligence and episodic memory are factor scores generated from multiple tasks (see SI Appendix, Supplemental Methods). Asterisks denote statistical significance, *P < 0.05; crosses denote marginal effects, ⁺P < 0.10; NS, not significant.