Figure 1. The impact of socioeconomic (SES) circumstances varies across childhood. Findings indicate that from the participants ages 1 to 10 years, there are statistically significant associations between housing status and future expression of glucocorticoid receptor mRNA. Participants whose families owned homes during these years express higher relative quantities of glucocorticoid receptor (GR) messenger ribonucleic acid (mRNA) during adolescence than participants whose families were renting (upper panel). For toll-like receptor 4 (TLR4), years 2 to 3 of life emerges as a critical period for SES. Participants whose families owned homes during these years express lower relative quantities of TLR4 mRNA during adolescence than participants whose families rented (lower panel). In both panels, the R² value on the y axis reflects the amount of variance in transcript uniquely explained by SES for that age, after statistical adjustment for age at study entry, self-reported ethnicity, and current economic circumstances.