CULTURE AND THE SOCIALIZATION OF CHILD CARDIOVASCULAR REGULATION AT SCHOOL ENTRY IN THE US
Dr. Jason Decaro is an associate professor at the University of Alabama who specializes in human development, evolutionary biology, and social epidemiology in East Africa, Central America, and the U.S. He received his Ph.D. from Emory University as a student of Dr. Carol Worthman, who is a Samuel Candler Dobbs Professor at Emory University. She received her Ph.D. in biological anthropology from Harvard University and specializes in human reproduction, development, and developmental epidemiology.
In this 2008 research article, Decaro and Worthman examine the link between childrearing practices and the child’s emotional response to normative social challenges, particularly the cardiovascular response. They conclude that culture shapes family ecology and this has a measurable effect on a child’s developing cardiovascular response. Ultimately, patterns in cardiovascular function can be linked to long-term health and well-being.
Specifically, the busyness of the mother’s schedule, rather than the child’s, was examined to see if there were any implications for the child’s respiratory sinus arrhythmia (RSA) following the normative social challenge of a school grade transition. RSA is a natural variation in an individual’s heart rate that occurs during the breathing cycle. RSAs are described in terms of vagal tones,
which refers to the activity of the vagus nerve. Increased vagal tone corresponds to diminished heart rate and more variability. RSAs are pronounced in children and are thought to be indicative of mental health. Research also suggests that children with more significant maternal attachments demonstrated higher vagal tones and, therefore, more social integration and empathetic receptiveness.
Decaro and Worthman hypothesized that 1) maternal busyness in year 1 (prior to grade transition) will affect the child’s RSA the following year, 2) maternal busyness will be linked to high maternal and family function, and 3) maternal mood, family dinner frequency, and parenting stress will also predict the child’s RSA in the following year.
The study consists of 38 families from metro Atlanta, GA. All children attended Pre-K the first year and kindergarten or some other form of primary schooling in the following year. Each family was visited four time during the child’s Pre-K year and data on daily schedule and maternal and child busyness was collected. Parenting stress and depression inventories were collected and frequency of family dinner was also collected as a marker for family function. In the last interview, a continuously monitored electrocardiogram (EKG) was conducted on the children as a baseline for future physiological data (prior to school grade transition). During the monitoring, children were asked to engage in a non-threatening interaction with two puppets to simulate social transition and interactions in the following grade year.
During the second year (after school grade transition), each family was visited again 3 to 11 weeks after the transition and the same data was collected.
Results and Discussion
The study found that, consistent with the first hypothesis, maternal busyness but not child busyness predicted the children’s parasympathetic regulations (RSA patterns) during the second year. The results showed a statically significant increase in children’s RSA in relation to maternal busyness, however, in married families only. (Remember that high RSA is a marker of low arousal). The study also confirmed the second hypothesis that high levels of maternal busyness correlated with positive maternal mood and less parenting stress. The results showed that increased maternal busyness correlated with lower maternal depression, as well as lower parent-child dysfunctional interactions/ parenting stress. The third hypothesis, however, was not confirmed by the study which showed that family dinner, parenting stress, and maternal mood were not predictors of children’s vagal regulation.
It was difficult for me to understand the psychological implications of the biomarker used in this study. My understanding is that vagal tones are thought to have a regulatory effect on social and emotional function. Therefore, a higher vagal tone, which we now see is observed in children whose mothers have low scores of depression and parenting stress, indicates that the child will exhibit less social inhibition and maybe deal with social normative challenges, like grade changes, better than children with low vagal tones. It would make sense then that RSAs and vagal tones are studied as a predictive measure. I did think that the RSA was interesting to learn about, especially in relation to child development. It plays into the parasympathetic nervous system and the idea of “rest and digest,” which is a fascinating topic.
I also feel like this article did a good job of explicitly stating its main points and using language that was easy for the reader to follow. A lot of the physiology was explained, too, which is important for biological anthropology.
- Why do you think there is a disconnect in the results between married families and single mothers?
- What does this study suggest about the state of a mother’s well-being and the well-being of her child?
- Can you think of any confounding factors that may have played a role in children’s physiological response that were not mentioned in the study?
- Are there any other biomarkers linked to early developmental experience that could be used?
- What are some cultural beliefs that shape childrearing practices?
- Decaro, J. A., & Worthman, C. M. (2008). Culture and the socialization of child cardiovascular regulation at school entry in the US. American Journal of Human Biology, 20(5), 572-583. doi:10.1002/ajhb.20782
- Gray, H. (2012). Anatomy of the human body. London, England: Bounty.
- (n.d.). Retrieved October 15, 2017, from http://pages.uoregon.edu/dslab/BPI.html