Table A4.

Intercorrelations Between County-Level, Family-Level, and Individual-Level Variables Used in the Regression Analyses.

Variables	Walking Alone	First Sentences	Count 10 Objects	Independent Toileting	Gender	Birth Year	Minority	Low Birth Weight	Preterm Birth	Hukou Before Age 3	Maternal Age at Delivery	Maternal Education	County-Level GDP Per Capita	Country-Level Urban Population %
Walking alone	1.000
First sentences	0.405	1.000
Count 10 objects	0.277	0.362	1.000
Independent toileting	0.237	0.329	0.456	1.000
Gender	−0.005	−0.048	−0.035	−0.028	1.000
Birth year	−0.167	−0.102	−0.261	−0.259	−0.014	1.000
Minority	0.076	−0.025	0.040	−0.031	−0.003	0.013	1.000
Low birth weight	0.173	0.100	0.248	0.146	0.014	−0.295	0.105	1.000
Preterm birth	0.017	−0.003	−0.014	−0.011	0.003	0.038	0.000	−0.026	1.000
Hukou before age 3	−0.098	−0.067	−0.199	−0.071	0.001	0.015	−0.086	−0.132	0.005	1.000
Maternal age at delivery	−0.004	0.019	0.008	0.002	−0.031	0.017	−0.017	0.006	0.020	0.067	1.000
Maternal education	−0.201	−0.139	−0.301	−0.155	0.017	0.240	−0.194	−0.278	0.011	0.436	−0.058	1.000
County-level GDP per capita	−0.153	−0.065	−0.215	−0.040	0.015	0.023	−0.209	−0.228	0.003	0.343	0.072	0.398	1.000
Country-level Urban population %	−0.082	−0.036	−0.173	−0.057	0.013	−0.023	−0.137	−0.141	0.011	0.509	0.053	0.330	0.505	1.000

Notes. Variable 1–10 are individual-level variables, from 11–12, family-level variables, and from 13–14, county-level variables.