The developmental course of salivary alpha-amylase and cortisol from 12 to 36 months: Relations with early poverty and later behavior problems

Highlights • We mapped the developmental trajectories of baseline salivary alpha-amylase (sAA) and cortisol from 12 to 36 months of age. • The largest changes in both systems were seen in the second year of life, with sAA increasing and cortisol decreasing. • Children residing in poor households exhibited lower initial levels of sAA, but not cortisol. • Initial levels of sAA predicted higher levels of internalizing behaviors at 36 months and both initial levels of and total change in sAA predicted higher levels of externalizing behaviors at 36 months.