We examined the increase in salivary cortisol from mid-morning to mid-afternoon in 151 children (3.0-4.5 yrs) in full-time home-based daycare. Compared to cortisol levels at home, increases were noted in the majority of children (63%) at daycare, with 40% classified as a stress response. Observations at daycare revealed that intrusive, over-controlling care was associated with the cortisol rise. For girls, the cortisol rise was associated with anxious, vigilant behavior, while for boys the rise was associated with angry, aggressive behavior. Child behavior did not mediate or moderate relations between care quality and the cortisol rise, except for evidence that boys scoring low on angry-aggressive behavior were more sensitive to variations in warm-supportive care than boys scoring high on this behavior.

Evidence that oral stimulants can produce interference effects in salivary cortisol assays has led to advice to avoid their use. However, in studies with young children, the use of these saliva-producing substances increases compliance with collection procedures. Four experiments are described to examine the effects of two commonly used stimulants, SweetTarts and Koolaid. Across these experiments, interference effects produced by different quantities of these stimulants (0.025, 0.1, and 0.2 g) and those produced in two commonly used assays, DELFIA and EIA, were explored. The impact of using cotton rolls soaked with an oral stimulant prior to saliva collection was also examined. In general, oral stimulants did not affect the rank ordering of cortisol values, as the results for stimulant-treated samples were highly correlated with those of untreated samples (approximately .90 for serially collected samples and .95 for aliquots of the same saliva pool). Depending on which assay was used, however, oral stimulants increased or decreased the cortisol levels reported, with effects sizes in the small to medium range. Thus, oral stimulants should not be used with only a portion of the subjects in a study, nor should researchers assay stimulant-treated samples from the same study using different assays. When used sparingly, oral stimulants can be employed without compromising the quality of salivary cortisol data.

No abstract

SummaryThe introduction of growth curve modeling into the field of neuroendocrinology has enabled researchers to examine mean patterns of change in unbalanced and/or incomplete repeated measures data. However, growth curve modeling assumes population homogeneity, or that all individuals follow roughly the same pattern of change, with differences expressed as deviation around the mean curve. Group-based trajectory modeling, in contrast, is designed for heterogeneous populations and as a result is able to identify atypical patterns of change over time that may exist within a population. To illustrate the strengths and weaknesses of each technique, we apply both to a sample of diurnal cortisol data measured at home in young children (N = 106, 46 male, M age = 3.81 years, SD = .24). We find three distinct trajectories of cortisol and demonstrate that the members of these trajectories are measurably different in terms of cortisol levels across context and time and in terms of the relationship between behavioral problems and parenting. At the same time, our growth curve analysis finds differential response patterns for high vs. low internalizing children with high vs. low parenting quality. We discuss these results in terms of their implications for the proper application of each method.

One hundred and twelve children, 56 toddlers and 56 preschoolers, were observed in their family child care settings to determine whether toddlers cared for in settings that also included preschoolers were, relative to the preschoolers, receiving more or less high-quality care and/or whether their functioning at child care appeared to be more or less dependent on aspects of the care providers' interactions with the children. Quality of care was analyzed along two dimensions: Sensitive/Supportive Care and Structured Care. Four indices of child functioning at child care were examined: integration in social activities, attention, positive mood, and angry/aggressive behavior. Results indicate that toddlers received less sensitive, supportive care than preschoolers in these mixed-age settings and toddlers were less socially integrated and less engaged in activities in the child care setting. Preschoolers displayed increased levels of angry/aggressive behavior relative to toddlers. In addition, associations of care provider behaviors and child functioning were larger for toddlers than preschoolers, suggesting that toddlers were more dependent on caregiver support for more successful functioning in these family child care settings. For both toddlers and preschoolers, care provider behavior and child functioning was generally poorer in settings with more children.

Children of ages 3 to 4.5 years (N = 107; 45 boys, 62 girls) were studied twice, 6 months apart, to examine whether the cortisol rise in child care at Time 1 (T1) was associated with (a) changes in anxious, vigilant behavior from T1 to Time 2 (T2) and (b) higher internalizing symptoms at T2. Controlling for measures of home environment and child care quality at T1, as well as for cortisol activity at T2, we obtained results indicating that behavioral inhibition moderated the associations between the rise in cortisol at T1 and child outcomes at T2 (i.e., anxious, vigilant behavior and internalizing symptoms). For both outcomes, the rise in cortisol at T1 became more positively predictive at increasing levels of behavioral inhibition. Specifically, at higher levels of behavioral inhibition, children with larger T1 cortisol increases expressed more internalizing symptoms than did children at lower levels of behavioral inhibition; in contrast, for those with low cortisol activity at T1, children with higher levels of inhibition expressed fewer internalizing symptoms than did children at lower levels of inhibition. In addition, children with higher levels of behavioral inhibition and lower cortisol activity at T1 exhibited reductions in anxious, vigilant behavior from T1 to T2, whereas at lower levels of behavioral inhibition, variations in the T1 cortisol rise bore no relation to changes in this behavior. These results suggest that the rise in cortisol at child care may have differential predictive value as a function of behaviorally inhibited temperament.

The INTMAN software system was designed to facilitate the collection of time-sampled data in field-based settings. INTMAN has a collection component and an analysis component. The collection component runs on Pocket 165Copyright 2006 Psychonomic Society, Inc.The first author and the first author's not-for-profit institution receive funds from license sales and therefore have a financial interest in the software described in this article. In this article, we describe the Interval Manager (INTMAN) software system for collecting timesampled observational data and present a preliminary application comparing the program with a traditional paper-and-pencil method. INTMAN is a computer-assisted alternative to traditional paperand-pencil methods for collecting fixed interval time-sampled observational data. The INTMAN data collection software runs on Pocket PC handheld computers and includes a desktop application for Microsoft Windows that is used for data analysis. Standard analysis options include modified frequencies, percent of intervals, conditional probabilities, and kappa agreement matrices and values. INTMAN and a standardized paper-and-pencil method were compared under identical conditions on five dimensions: setup time, duration of data entry, duration of interobserver agreement calculations, accuracy, and cost. Overall, the computer-assisted program was a more efficient and accurate data collection system for time-sampled data than the traditional method.