Family Relationship and Environment Influences on Children’s Cortisol Levels Karina R. Horowitz*, Kathryn Lemery-Chalfant*, Jane E. Schreiber+ & H. Hill Goldsmith+ *ASU Child Emotion Center, Arizona State University +Department of Psychology, University of Wisconsin-Madison **This research was supported by the National Institute of Mental Health Grant (R01-MH59785) to H. Hill Goldsmith and Kathryn Lemery-Chalfant Introduction Results • Correlations • 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.11. • 1. Basal Cortisol - • 2. Recovery Cortisol.06 - • Parenting Variables • 3. CRPR- Encourage Expression.01 .11* - • 4. CRPR- Control by Guilt .12* -.13* -.03 - • 5. CRPR- Authoritarian Control .13* -.14* -.14* .40* - • Sibling Variables • 6. SRQ- nurturance by sibling .20* -.07 .03 .02 - .04 - • 7. SRQ- affection .26* -.08 .13 .01 .08 .38* - • 8. SRQ- antagonism .18* -.08 -.02 -.04 .01 .01 -.48* - • 9. SRQ- admiration of sibling .21* -.12 .11 -.06 .07 .48* -.83* -.16* - • 10. SRQ- admiration by sibling .18* -.11 .01 -.07 .10 .37* -.72* -.07 .85* - • 11. SRQ- dominance by sibling .02 .30* .10 .18 .04 -.11 -.17 .28* .19 .24* _- *p <.05; +p <.10 Regressions • We conducted a series of regressions to predict basal and recovery cortisol from the two sets of significant predictors (parenting and sibling relationship) separately. • For the sibling-basal cortisol regression, we collapsed across positive (nurturance, affection, admiration of, admiration by) and negative (antagonism) aspects of the sibling relationship that had significant first order correlations with basal cortisol, given the high multicollinearity. Positive aspects of the relationship significantly predicted cortisol while negative aspects did not (Figure 1). • For the parenting-basal cortisol regression, CRPR- authoritarian control was a significant predictor of cortisol while CRPR- control by guilt was not a significant predictor (Figure 2). • For the sibling-recovery cortisol regression, dominance by a sibling was a significant predictor, and the only significant first order correlation with recovery cortisol. For the parenting-recovery cortisol regression, neither of the predictors, CRPR or negative discipline, were significant predictors although the overall regression was significant. • Family environment, and more specifically parenting, can have direct effects on child development that are both permanent and of great consequence (Luecken & Lemery, 2004). Family relationships influence all types of child outcomes including the development of stress response systems (Adam, Klimes-Dougan, & Gunnar, in press). • Most studies that investigate children’s stress hormone levels investigate childhood events such as living in an orphanage or children’s response to starting school (Davis, Donzella, Krueger & Gunnar, 1999; Gunnar, Morrison, Chisholm & Schuder, 2001). This study is innovative in that it examines how children’s cortisol levels are related to their family relationships. • Two different theoretical models could explain this tie between relationships and child stress physiology. Attachment theory uses the child-caregiver relationship to characterize children’s reactions to stressful events. Insecureattachment characterized by inconsistency in caregiving is stressful. Furthermore, this insecurity reveals itself in the child’s internal working model of future relationships. • A second perspective that may explain the association between early relationships and children’s stress responses is social learning theory. The main premise underlying this theory is that children imitate what they see others do. If mother views the world as stressful and reacts in a way that allows children to infer that she thinks the world is stressful, children will learn that the world is stressful. Children could also model the stress reactions of their siblings. • We measured basal, reactive, and recovery cortisol. These measures tap typical cortisol patterns, peak cortisol response, and the time or slope from peak response to baseline levels, respectively. Each of these gives independent information concerning the stress response system. • Stressful relationships with siblings and parents may relate to higher basal cortisol levels or slower stress recovery. Positive aspects of relationships may also be protective and relate to lower basal cortisol and quicker recovery. • Previous research has examined parenting (e.g., Gunnar et al., 1992; Pendry & Adam, in press) and its association with children’s cortisol levels but typically in preschool-aged children. Further, we measure recovery as well as basal cortisol, and include the sibling as well as parent-child relationship. Figure 1. Positive SRQ Β= .22* Basal Cortisol Negative SRQ Β= .13 CRPR- Authoritarian Control Figure 2. Β= .10* Basal Cortisol CRPR- Control by Guilt Β= .07 Method • Participants • We used a selected sample of twins and their parents from the Wisconsin Twin Project, an ongoing, longitudinal study of the development of psychopathology in middle childhood. Sample size for each cluster of measures are the following: parenting (N=504), cortisol (N range= 383-405), sibling relationship (N= 180). • Mean age of twins: 8.4 years (range 5.6 to 12.1 years) • Ethnic make-up of the families: 97% Caucasian and 3% other or mixed race • Basal Cortisol Collection • Saliva was collected at two time points (between 3 and 7 pm; before bedtime) on 3 consecutive days using salivette tubes • Families were instructed not to eat or drink prior to saliva collection, to store samples in the freezer immediately after collection, and were given a form to record information about what time samples were collected and whether children were feeling ill or taking any medication. • No significant differences were found for children taking medication • Recovery Cortisol Collection • Researchers collected salivary cortisol three times during a home visit using salivette tubes. Children's cortisol levels decreased over the course of the visit indicating an anticipatory cortisol response to the home visit. Later cortisol levels were subtracted from earlier levels to get an estimate of children's cortisol recovery. Relationship Measures Child- Rearing Practices Report (CRPR; Block, 1965). The CRPR includes items tapping child-rearing attitudes, values, behaviors, and goals. We modified the original Q-sort format in which parents arrange each item on a 7-point scale from “most descriptive” to “least descriptive.” The modified CRPR asks caregivers in a questionnaire format about their attitudes on raising children using a 6-point scale. Higher scores indicate more of that practice. Sibling Relationship Questionnaire (SRQ; Buhrmester & Furman, 1990). Twins reported on frequency and occurrence of positive and negative behaviors in the sibling relationship. Twin reports were obtained using a puppet interview format similar to the Berkeley Puppet Interview (Measelle et al., 1998). Researchers later coded the interview using a 7-point scale. Higher scores indicate more of that relationship quality. Discussion • We found that aspects of the sibling relationship and parenting are associated with both basal and recovery cortisol levels in children • Contrary to expectation, more positive sibling relationships were associated with a higher basal cortisol level. More dominance by a sibling was associated with slower cortisol recovery. Future research should involve more measures of the sibling relationship in order to further understand these findings. Given that previous literature has found that sibling relationships impact child adjustment (e.g., Pike et al, 2005), cortisol levels may mediate the link between the relationship and child adjustment. • In line with previous findings (e.g., Pendry & Adam, in press), more controlling parenting and the use of negative discipline were associated with higher basal cortisol levels and a slower cortisol recovery. • Thus, parent-child and sibling relationships are associated with a child’s stress response possibly explained by attachment theory or social learning theory. • Future analyses with these data: • Multi-level modeling to control for the interdependence of twin data • Examine both positive and negative predictors of stress responsivity, i.e., parental warmth, hostility, and intrusiveness; sibling competition and cooperation • Predict individual children’s recovery slope using growth curve modeling. This statistical tool has the following advantages: • added statistical power • high tolerance for missing data • adjustment for within person and within day correlations **References available upon request
Contact Information: Karina R. Horowitz Arizona State University Department of Psychology PO Box 871104 Tempe, AZ 85287-1104 email@example.com Please do not cite without author’s permission. References Adam, E.K., Klimes-Dougan, B., & Gunnar, M. (in press). Social regulation of stress physiology in infancy, childhood and adulthood. To appear in:Donna Coch, Geraldine Dawson & Kurt Fischer (Eds) Human Behavior andthe Developing Brain: Atypical Development. Guilford Press. Block, J.H. (1965). The child-rearing practices report: A technique for evaluating parental socialization orientations. Berkeley: University of California Institute of Human Development. Buhrmester, D. & Furman, W. (1990).Perceptions of sibling relationships during Middle childhood and adolescence. Child Development, 61, 1387-1398. Davis, E.P., Donzella, B., Krueger, W.K., & Gunnar, M.R. (1999). The start of a new school year: Individual differences in salivary cortisol response in relation to child temperament.Developmental Psychobiology, 35, 188-196. Gunnar, M.R., Morison, Chisholm & Schuder, (2001). Salivary cortisol levels in children adopted from Romanian orphanages. Development and Psychopathology; Special Issue: Stress and development: Biological and psychological consequences, 12, 611-628. Gunnar, M.R., Larson, M.C., Hertsgaard, L., Harris, M.C., & Broderson, L.(1992). The stressfulness of separation among nine-month-old infants: Effects of social context variables and infant temperament. Child Development, 63, 290-303. Measelle, J.R., Ablow, J.E., Cowan, P.A., & Cowan, C.P. (1998). Assessing young children's views of their academic, social, and emotional lives: An evaluation of the self-perception scales of the Berkeley Puppet Interview. Child Development, 69, 1556-1576. Pendry, P. & Adam, E. K. (Under Review). Hormones under siege? Associations between interparental discord, parenting quality, parent emotion and cortisol levels in adolescent and kindergarten-aged children. Submitted to International Journal of Behavioral Development. Pike, A., Coldwell, J., & Dunn, J. (2005). Sibling relationship in early/middle childhood: Links with individual adjustment. Journal of Family Psychology, 19, 523-532.