A latent State Trait Model of Cortisol in NormallyDeveloping Youth

Research relating salivary cortisol levels with

internalizing and externalizing behavior problems in

youth has yielded inconsistent results, likely due to

the high day-to-day variation in stress regulation.

Understanding stability in this changing system may

require an analytical strategy that separates

variance in cortisol levels attributable to trait- or

"basal" versus state- or "situationally-specific¿

sources. Early morning saliva samples were obtained

from 654 youth (range 6-16 yrs ) on two successive

days one year apart. Latent state trait modeling

revealed that 70% of the variance in cortisol levels

could be attributed to state-like sources, and 28% to

trait-like sources. Higher levels of externalizing

problems were consistently associated with lower

basal cortisol in boys. This finding is consistent

with studies of at-risk and clinical groups. The

present findings confirm the relationship spans both

normative and atypical child development, and

supports speculations that boys with low cortisol may

be at risk for externalizing behavior problems.