Research shows that head size growth in the first year of life relates to intelligence later (Gale et al., 2006). It doesn't matter how large the baby's head was at birth, it's what happens in the first year after birth that matters most.
How do babies grow after birth?
When mothers stop touching their infants, DNA synthesis stops, growth hormone diminishes (Schaunberg, 1995). Physiologically, the baby goes into "survival mode."
Our ancestors carried and held (all the time) and slept with their babies, maximizing growth.
What else helps the baby grow?
Breastmilk. Use of infant formula is risky. It is greatly inferior to breastmilk in so many ways (I'll put this in a later blog). It linked to poor development of brain neurotransmitters and of the immune system which influence how the brain functions. Formula feeding is a risk factor for all sorts of diseases, large and small, including diabetes.
Breastfeeding encourages right brain development, the source of social emotions and practical intelligence. Breast milk fosters more efficient function=more intelligence.
Even adopting moms can breastfeed!
What deters growth?
Distress. Crying kills neuronal connections.When the stress-response system kicks in, goodbye synapses. But the "other brain" is also affected. Too much stress suppresses glial cell division--and glial cells take care of myelinization at developmental plateaus (myelin is the capstone for a neuron and facilitates communication with other neurons).
It is advisable for a parent to be like an ancient traditionalist---anticipate the baby's needs by its movements, its restlessness. Don't let it get upset before tending to its needs. Figure out the specific holding and rocking patterns that it prefers and that calm it down.
(Traditional caregivers are even able to anticipate elimination in their babies when they carry them around, circumventing the need for diapers. Of course, most of the time we cannot follow this practice in the modern world!)
It's not surprising that these parenting principles have been around for 30 million years among catarrhine mammals (of which we are a part). These practices are shown to bring about intelligence by fostering a well-functioning body and brain.
Take home message: If you want a smart baby...
1, (Almost) NEVER PUT IT DOWN!
2, Keep it CALM.
3. Feed it MOTHER's milk. Plan and work to breastfeed for at least a year if not longer (ancestral patterns were 2-5 years with an average weaning age of 4; Hewlett & Lamb, 2005).
POSTS ON PARENTING ISSUES AND CHILD DEVELOPMENT:
INFANT SLEEP AND SLEEP TRAINING:
SERIES ON CHILD FLOURISHING*
1. Kindness in Kids and the Nature-Nurture Debate (Dr. Sarina Saturn)
2. Why Synchronize and Bond With Your Children (Dr. Ruth Feldman)
3. “I want it—now!” How Children Learn Self-Control (Dr. Julie Braungart-Rieker)
4. Why Kids Should Be Protected from Toxic Stress (Dr. Bruce Perry)
5. “Mr. Mom” The New (or Old?) Normal (Dr. Lee Gettler)
6. Why Dad’s “Talk” is Important (Dr. Holly Brophy-Herb)
7. Conflict in the Family: Why Mom and Dad Should Say “Sorry” (Dr. Mark Cummings)
8. Domination or Partnership? How Does Your Family Stack Up? (Dr. Riane Eisler)
9. Why Carefully Invest Daily in a Child (Dr. Robin Nelson)
ALSO SEE: What is Child Flourishing?
NOTE on BASIC ASSUMPTIONS:
When I write about human nature, I use the 99% of human genus history as a baseline. That is the context of small-band hunter-gatherers. These are “immediate-return” societies with few possessions who migrate and forage. They have no hierarchy or coercion and value generosity and sharing. They exhibit both high autonomy and high commitment to the group. They have high social wellbeing. See comparison between dominant Western culture and this evolved heritage in my article (you can download from my website):
Narvaez, D. (2013). The 99 Percent—Development and socialization within an evolutionary context: Growing up to become “A good and useful human being.” In D. Fry (Ed.), War, Peace and Human Nature: The convergence of Evolutionary and Cultural Views (pp. 643-672). New York: Oxford University Press.
When I write about parenting, I assume the importance of the evolved developmental niche (EDN) for raising human infants (which initially arose over 30 million years ago with the emergence of the social mammals and has been slightly altered among human groups based on anthropological research).
The EDN is the baseline I use for determining what fosters optimal human health, wellbeing and compassionate morality. The niche includes at least the following: infant-initiated breastfeeding for several years, nearly constant touch early, responsiveness to needs so the young child does not get distressed, playful companionship with multi-aged playmates, multiple adult caregivers, positive social support, and soothing perinatal experiences.
All EDN characteristics are linked to health in mammalian and human studies (for reviews, see Narvaez, Panksepp, Schore & Gleason, 2013; Narvaez, Valentino, Fuentes, McKenna & Gray, 2014; Narvaez, 2014) Thus, shifts away from the EDN baseline are risky and must be supported with longitudinal data looking at wellbeing in children and adults. My comments and posts stem from these basic assumptions.
My research laboratory has documented the importance of the EDN for child wellbeing and moral development with more papers in the works see (my Website to download papers):
Narvaez, D., Gleason, T., Wang, L., Brooks, J., Lefever, J., Cheng, A., & Centers for the Prevention of Child Neglect (2013). The Evolved Development Niche: Longitudinal Effects of Caregiving Practices on Early Childhood Psychosocial Development. Early Childhood Research Quarterly, 28 (4), 759–773. Doi: 10.1016/j.ecresq.2013.07.003
Narvaez, D., Wang, L., Gleason, T., Cheng, A., Lefever, J., & Deng, L. (2013). The Evolved Developmental Niche and sociomoral outcomes in Chinese three-year-olds. European Journal of Developmental Psychology, 10(2), 106-127.
Also see these books for selected reviews:
Evolution, Early Experience and Human Development (Oxford University Press)
Ancestral Landscapes in Human Evolution (Oxford University Press)
Catharine R. Gale, PhD, Finbar J. O'Callaghan, PhD, Maria Bredow, MBChB, Christopher N. Martyn, DPhil and the Avon Longitudinal Study of Parents and Children Study Team (October 4, 2006). "The Influence of Head Growth in Fetal Life, Infancy, and Childhood on Intelligence at the Ages of 4 and 8 Years". PEDIATRICS Vol. 118 No. 4 October 2006, pp. 1486-1492. http://pediatrics.aappublications.org/cgi/content/short/118/4/1486.
Hewlett, B., & Lamb, M. (2005). Hunter-gatherer childhoods.New York: Aldine.
Schanberg, S. (1995). The genetic basis for touch effects. In T. Field (Ed.), Touch and Early Experience (pp. 67-80). Mahwah, NJ: Erlbaum.