The Village Effect: How Face-to-Face Contact Can Make Us Healthier and Happier (49 page)

47.
Kelly Musick and Ann Meier, “Assessing Causality and Persistence in Associations between Family Dinners and Adolescent Well-being,”
Journal of Marriage and Family
74, no. 3 (2012); Ann Meier and Kelly Musick, “Variation in Associations between Family Dinners and Adolescent Well-being,”
Journal of Marriage and Family
76, no. 1 (2014).

48.
Franko et al., “What Mediates the Relationship.”

49.
Snow and Beals, “Mealtime Talk”; Vibeke Aukrust and C. Snow, “Narratives and Explanations during Mealtime Conversations in Norway and the U.S.,”
Language in Society
27, no. 2 (1998).

50.
Adam Gilden Tsai and Thomas A. Wadden, “Systematic Reveiw: An Evaluation of Major Commercial Weight Loss Programs in the United States,”
Annals of Internal Medicine
142, no. 1 (2005); Stanley Heshka et al., “Weight Loss with Self-Help Compared with a Structured Commercial Program: A Randomized Trial,”
Journal of the American Medical Association
289, no. 14 (2003).

51.
Linda Mercandante,
Victims and Sinners
(Westminster: John Knox Press, 1996).

52.
Chris Norris, “Hitting Bottom,”
New York Times Magazine
, January 3, 2010.

53.
Salvy et al., “The Presence of Friends”; Thomas J. Dishion, D. W. Andrew, and L. Crosby, “Antisocial Boys and Their Friends in Early Adolescence: Relationship Characteristics, Quality, and Interactional Process,”
Child Development
66 (1995); N. A. Christakis and J. H. Fowler, “The Collective Dynamics of Smoking in a Large Social Network,”
New England Journal of Medicine
358, no. 21 (2008).

54.
J. Niels Rosenquist et al., “The Spread of Alcohol Consumption Behavior in a Large Social Network,”
Annals of Internal Medicine
152, no. 7 (2010).

55.
Bryan Curtis, “Man-Cave Masculinity,”
Slate
, October 3, 2011.

56.
Daniel Okrent,
Last Call: The Rise and Fall of Prohibition
(New York: Scribner, 2010). 340–41.

CHAPTER 5: BABY CHEMISTRY

1.
  Sue Carter, a neuroscientist whose research revealed the powerful impact of neuropeptides such as oxytocin on pair bonding in prairie voles, has shown that oxytocin not only facilitates birth, lactation, social trust, and the formation of social bonds among mammals, but it also promotes the ability to sit still. And it’s a two-way street. These activities both promote oxytocin release (and immobility) and require it. When oxytocin is given artificially, it enhances “the capacity for immobility.” C. Sue Carter et al., “Consequences of Early Experiences and Exposure to Oxytocin and Vasopressin Are Sexually Dimorphic,”
Developmental Neuroscience
31 (2009).

2.
  
Cria Perrine, “Breastfeeding Report Card—United States 2011,” Centers for Disease Control and Prevention, 2011,
http://www.cdc.gov/breastfeeding/pdf/2011breastfeedingreportcard.pdf
.

3.
  Hanna Rosin, “The Case Against Breast-Feeding,”
The Atlantic
, April 2009.

4.
  Sarah Bosely, “Six Months of Breastmilk Alone Is Too Long and Could Harm Babies, Scientists Now Say,”
The Guardian
, January 14, 2011; Mary Fewtrell et al., “When to Wean? How Good Is the Evidence for Six Months of Exclusive Breastfeeding?”
British Medical Journal
342 (2011).

5.
  Rosin, “The Case Against Breast-Feeding.”

6.
  A little more than half of Canadian mothers (51%) are breastfeeding their babies exclusively at three months postpartum, and the same proportion persist with some breastfeeding at six months of age. At six months of age, the rates of any breastfeeding in the United Kingdom are half that (21%)—and closer to the American rates. Beverley Chalmers and Catherine Royale, eds.,
What Mothers Say: The Canadian Maternity Experiences Survey
(Ottawa: Public Health Agency of Canada, 2009).

7.
  Breastfeeding has also been said to protect against obesity, asthma, diabetes, eczema, heart disease, and various cancers in babies, but the evidence for that is more controversial. And non-nutritional influences may be spinning the dice regarding the link between breastfeeding and intelligence. These days, well-educated mothers are the ones most likely to breastfeed their babies, so the cognitive boons associated with the practice may have more to do with the mother’s genetic, socioeconomic, and educational background—and with the increased time and attention she gives her baby—than with the biochemical composition of breast milk per se. Geoff Der, G. David Batty, and Ian J. Deary, “Effect of Breast Feeding on Intelligence in Children: Prospective Study, Sibling Pairs Analysis and Meta-analysis,”
British Medical Journal
(2006); A. Sacker et al., “Breast Feeding and Intergenerational Social Mobility: What Are the Mechanisms?”
Archives of Disease in Childhood
98 (2013); K. Heikkila et
al., “Breast Feeding and Child Behaviour in the Millennium Cohort Study,”
Archives of Disease in Childhood
96 (2011).

8.
  Jill Lepore, “Baby Food: If Breast Is Best, Why Are Women Bottling Their Milk?”
New Yorker
, January 19, 2009.

9.
  Michael S. Kramer et al., “Breastfeeding and Child Cognitive Development: New Evidence from a Large Randomized Trial,”
Archives of General Psychiatry
65, no. 5 (2008); Michael S. Kramer et al., “Promotion of Breastfeeding Intervention Trial (PROBIT): A Randomized Trial in the Republic of Belarus,”
Journal of the American Medical Association
285, no. 4 (2001).

Interestingly, a study published by psychologist Avshalom Caspi and his colleagues in 2007 has shown that breastfeeding only boosts intelligence in children possessing certain gene variants, providing evidence that environmental influences like breastfeeding have the effect of “switching on” certain genes—while having almost no impact on those who haven’t been dealt that genetic hand. Avshalom Caspi et al., “Moderation of breastfeeding effects on the IQ by genetic variation in fatty acid metabolism,”
PNAS Proceedings of the National Academy of Sciences of the United States of America
104, no. 47 (2007).

10.
Kramer mentioned one exception to his statement that there are no good data showing a cognitive effect deriving from the components of human breast milk. One study of preemies, done by Alan Lucas and his colleagues at University College London in the early nineties, found that premature babies fed banked breast milk through a gastric tube showed later cognitive gains (at ages seven to eight) compared to those who received preterm formula. The authors point out that one reason this might be true of premature infants in particular is that “they may be especially sensitive to early nutrition” compared to full-term babies, whose neurodevelopment is comparatively more mature at birth. Alan Lucas et al., “Breast Milk and Subsequent Intelligence Quotient in Children Born Preterm,”
Lancet
339 (1992).

11.
Melvin Konner,
The Evolution of Childhood: Relationships, Emotion, Mind
(Cambridge, MA: Belknap Press, 2010); A. N. Meltzoff and M. K
Moore, “Imitation of Facial and Manual Gestures by Human Neonates,”
Science
198 (1997).

12.
Social interaction is so critical for human development that infants placed in orphanages, where they spend hours alone in their cribs, experience developmental delays even though they are provided with other life essentials such as food, formula, and water. Over history, including most of the twentieth century, children have paid a high price for the common omission of social contact as a prerequisite for human development and survival.

13.
Our primate ancestors mastered this trick too, though in reverse. By recording and playing back sound clips of different juveniles in distress, Dorothy Cheney and Robert Seyfarth, a husband-and-wife primatology team, discovered that adult female vervet monkeys and baboons can pick out their own offspring’s calls from all the others (the point at which they started moving with great purpose toward the loudspeaker). Adult females not only recognized their own offspring’s alarm calls but would look intently at another mother whose child’s screams they’d just heard. Dorothy L. Cheney and Robert M. Seyfarth,
Baboon Metaphysics: The Evolution of a Social Mind
(Chicago: University of Chicago Press, 2007).

14.
Maude Beauchemin et al., “Mother and Stranger: An Electrophysiological Study of Voice Processing in Newborns,”
Cerebral Cortex
21, no. 8 (2011); Anne McIlroy, “Infants Give Mother Tongue New Meaning,”
Globe and Mail
, December 17, 2010; William Raillant-Clark, “Mom’s Voice Plays Special Role in Activating Newborn’s Brain,”
Forum
[University of Montreal], December 16, 2010.

15.
Patricia Kuhl, “Is Speech Learning ‘Gated’ by the Social Brain?”
Developmental Science
10, no. 1 (2007); Michael H. Goldstein, Andrew P. King, and Meredith J. West, “Social Interaction Shapes Babbling,”
Proceedings of the National Academy of Sciences of the United States of America
100, no. 13 (2003).

16.
In an amazing experiment designed to test when babies lose the ability to distinguish sounds that don’t exist in their native language (e.g., the
p/b
distinctions that Spanish speakers hear but adult native English speakers
don’t), Patricia Kuhl exposed nine-month-olds from English homes to someone speaking to them in Mandarin. As Perri Klass reported in her
New York Times
column, “Exposing English-language infants in Seattle to someone speaking to them in Mandarin helped those babies preserve the ability to discriminate Chinese language sounds, but when the same ‘dose’ of Mandarin was delivered by a television program or an audiotape, the babies learned nothing.” Perri Klass, “Hearing Bilingual: How Babies Sort Out Language,”
New York Times
, October 11, 2011.

Patricia Kuhl, Feng-Ming Tsao, and Huei-Mei Liu, “Foreign-language experience in infancy: Effects of short-term exposure and social interaction on phonetic learning,”
PNAS Proceedings of the National Academy of Sciences of the United States of America
100, no. 15 (2003).

17.
Joni N. Saby, Andrew N. Meltzoff, and Peter J. Marshall, “Infants’ Somatotopic Neural Responses to Seeing Human Actions: I’ve Got You Under My Skin,”
PLOS One
8, no. 10 (2013); Joni N. Saby, Peter J. Marshall, and Andrew Meltzoff, “Neural Correlates of Being Imitated: An EEG Study in Preverbal Infants,”
Social Neuroscience
7, no. 6 (2012). Thanks are due to Andrew Meltzoff for taking the time to explain his recent work and send me these studies.

18.
Deborah Blum,
Love at Goon Park: Harry Harlow and the Science of Affection
(Cambridge, MA: Perseus, 2002).

19.
Ibid.; Luther Emmett Holt,
The Care and Feeding of Children: A Catechism for the Use of Mothers and Children’s Nurses
(New York: D. Appleton, 1907).

20.
Nicholas D. Kristof, “A Poverty Solution that Starts with a Hug,”
New York Times
, January 7, 2012.

21.
Holt,
The Care and Feeding of Children
.

22.
C. Celeste Johnston, Marsha Campbell-Yeo, and Francoise Filion, “Paternal vs Maternal Kangaroo Care for Procedural Pain in Preterm Neonates: A Randomized Crossover Trial,”
Archives of Pediatric Adolescent Medicine
165, no. 9 (2011).

23.
Celeste Johnston is one of the swim-team friends first mentioned in
Chapter 1
as having played a key role in Sylvie’s face-to-face social
network. Like a number of female social scientists, she sustains a deep academic interest in social bonds while investing in a rich personal network of her own.

24.
Kerstin Erlandsson et al., “Skin to Skin Care with the Father after Cesarean Birth and Its Effect on Newborn Crying and Prefeeding Behavior,”
Birth: Issues in Perinatal Care
34, no. 2 (2007).

25.
Monica Krayneck, Mona Patterson, and Christina Westbrook, “Baby Cuddlers Make a Difference,”
Journal of Obstetric, Gynecologic and Neonatal Nursing
41, no. 1 (2012); Harvard Medical School Beth Israel Deaconess Medical Center, “NICU Programs Benefit Premature Babies and Their Parents,” July 2010,
http://www.bidmc.org/YourHealth/HealthNotes/ObstetricsandGynecology/HighRiskOB/NICUProgramsBenefitPrematureBabiesandTheirParents.aspx
.

26.
Susan Pinker,
The Sexual Paradox: Extreme Men, Gifted Women, and the Real Gender Gap
(Toronto: Random House Canada, 2008); Ruth Feldman et al., “Comparison of Skin-to-Skin (Kangaroo) and Traditional Care: Parenting Outcomes and Preterm Infant Development,”
Pediatrics
110, no. 1 (2002).

27.
I am indebted to Alison Gopnik, who reminded me of the importance of alloparenting when describing the effects of touch and intimate social contact on the developing brain. Sarah Blaffer Hrdy,
Mothers and Others: The Evolutionary Origins of Mutual Understanding
(Cambridge, MA: Bellknap Press, 2009); Sarah Blaffer Hrdy, “Comes the Child Before Man: Development’s Role in Producing Selectable Variation,”
Evolutionary Anthropology
21 (2012); Kristen Hawkes, “What Makes Us Human? Grandmothers and Their Consequences,”
Evolutionary Anthropology
21 (2012).

28.
Evalotte Morelius, Elvar Theodorsson, and Nina Nelson, “Salivary Cortisol and Mood and Pain Profiles during Skin-to-Skin Care for an Unselected Group of Mothers and Infants in Neonatal Intensive Care,”
Pediatrics
116, no. 5 (2005); N. M. Hurst et al., “Skin-to-Skin Holding in the Neonatal Intensive Care Unit Influences Maternal Milk Volume,”
Journal of Perinatology
17, no. 3 (1997).

29.
In one Israeli study that compared a group of seventy-three preemies and their mothers who practiced kangaroo care with a matched group of seventy-three preemies whose mothers did not, psychologist Ruth Feldman and her colleagues discovered that kangaroo care shortly after birth boosts the baby’s cognitive development six months later. Feldman et al., “Comparison of Skin-to-Skin (Kangaroo) and Traditional Care.”