by Emily Oster
12. Occasionally, an academic paper will come out that will restate this claim. An example is one published in 2014 in the journal Translational Neurodegeneration (Hooker BS. Measles-mumps-rubella vaccination timing and autism among young African American boys: A reanalysis of CDC data. Transl Neurodegener 2014;3:16). The author of this paper uses a small sample of children and a case-control design—taking some kids with autism and matching them to some children without autism. He argues that for African American boys in particular the risk of autism is higher if they get the MMR vaccine before 36 months.
This paper is an almost comically bad example of how to do statistics. The author finds no effect overall, so he moves to looking for effects in little groups. This is not an approved way to do research—even if there is truly no relationship, you’ll almost always be able to find some small group where there is an effect, just by chance. It turns out the relationship is robust only for African American boys who are low birth weight, and only when the author considers vaccinations before 36 months, not before 18 months or 24 months. There is no information on sample size reported (also a no-no in paper writing), but it seems like some of these relationships are based on 5 or 10 children total.
Moreover, the author of this paper—Brian Hooker—is a well-known antivaccination advocate who, like Wakefield, has an interest in promoting the antivaccination viewpoint since it benefits his expert litigation practice. This information was not fully disclosed in the article, as it should have been, and because of this conflict and the statistical problems, this paper was retracted, just like the Wakefield paper, but, of course, not before it got a lot of coverage and scaremongering in the media. It is unfortunate that there is not more interest in covering the many well-conducted and large studies that show this relationship is complete bunk.
13. Omer SB, Pan WKY, Halsey NA, Stokley S, Moulton LH, Navar AM, Pierce M, Salmon DA. Nonmedical exemptions to school immunization requirements: Secular trends and association of state policies with pertussis incidence. JAMA 2006;296(14):1757–63.
14. Verity CM et al. Febrile convulsions in a national cohort followed up from birth.
15. Pesco P, Bergero P, Fabricius G, Hozbor D. Mathematical modeling of delayed pertussis vaccination in infants. Vaccine 2015;33(41):5475–80.
CHAPTER 9: STAY-AT-HOME MOM? STAY-AT-WORK MOM?
1. For a review, see http://web.stanford.edu/~mrossin/RossinSlater_maternity_family_leave.pdf.
2. Goldberg WA, Prause J, Lucas-Thompson R, Himsel A. Maternal employment and children’s achievement in context: A meta-analysis of four decades of research. Psychol Bull 2008;134(1):77–108.
3. Goldberg WA et al. Maternal employment and children’s achievement in context.
4. These studies also show that when you look at changes in test scores between years it doesn’t matter what the working configuration is, suggesting that it may be underlying differences that matter.
5. Ruhm CJ. Maternal employment and adolescent development. Labour Econ 2008;15(5):958–83.
6. Marantz S, Mansfield A. Maternal employment and the development of sex-role stereotyping in five- to eleven-year-old girls. Child Dev 1997;48(2):668–73. McGinn KL, Castro MR, Lingo EL. Mums the word! Cross-national effects of maternal employment on gender inequalities at work and at home. Harvard Business School 2015;15(194).
7. Rossin-Slater M. The effects of maternity leave on children’s birth and infant health outcomes in the United States. J Health Econ 2011;30(2):221–39.
8. Rossin-Slater M. Maternity and Family Leave Policy. Natl Bureau Econ Res 2017.
9. Rossin-Slater M. Maternity and Family Leave Policy.
10. Carneiro P, Loken KV, Kjell GS. A flying start? Maternity leave benefits and long-run outcomes of children. J Pol Econ 2015;123(2):365–412.
11. This is an approximate calculation based on a medium-tax-level state.
CHAPTER 10: WHO SHOULD TAKE CARE OF THE BABY?
1. NICHD Early Childcare Research Network. Early childcare and children’s development prior to school entry: Results from the NICHD Study of Early Childcare. AERJ 2002;39(1):133–64.
2. Belsky J, Vandell DL, Burchinal M, et al. Are there long-term effects of early childcare?. Child Dev 2007;78(2):681–701.
3. NICHD. Type of childcare and children’s development at 54 months. Early Childhood Res Q 2004;19(2):203–30.
4. NICHD. Early childcare and children’s development prior to school entry.
5. Belsky J et al. Are there long-term effects of early childcare?
6. Broberg AG, Wessels H, Lamb ME, Hwang CP. Effects of day care on the development of cognitive abilities in 8-year-olds: A longitudinal study. Dev Psychol 1997;33(1):62–69.
7. Huston AC, Bobbitt KC, Bentley A. Time spent in childcare: How and why does it affect social development? Dev Psychol 2015;51(5):621–34.
8. NICHD. The effects of infant childcare on infant-mother attachment security: Results of the NICHD Study of Early Childcare. Child Dev 1997;68(5):860–79.
9. Augustine JM, Crosnoe RL, Gordon R. Early childcare and illness among preschoolers. J Health Soc Behav 2013;54(3):315–34. Enserink R, Lugnér A, Suijkerbuijk A, Bruijning-Verhagen P, Smit HA, Van Pelt W. Gastrointestinal and respiratory illness in children that do and do not attend child day care centers: A cost-of-illness study. PLoS ONE 2014;9(8):e104940. Morrissey TW. Multiple childcare arrangements and common communicable illnesses in children aged 3 to 54 months. Matern Child Health J 2013;17(7):1175–84. Bradley RH, Vandell DL. Childcare and the well-being of children. Arch Pediatr Adolesc Med 2007;161(7):669–76.
10. Ball TM, Holberg CJ, Aldous MB, Martinez FD, Wright AL. Influence of attendance at day care on the common cold from birth through 13 years of age. Arch Pediatr Adolesc Med 2002;156(2):121–26.
CHAPTER 11: SLEEP TRAINING
1. Ramos KD, Youngclarke DM. Parenting advice books about child sleep: Cosleeping and crying it out. Sleep 2006;29(12):1616–23.
2. Narvaez D. Dangers of “Crying It Out.” Psychology Today. December 11, 2011. https://www.psychologytoday.com/blog/moral-landscapes/201112/dangers-crying-it-out.
3. This review overall includes more than 2,500 children across 52 studies, all employing variations on sleep training. Some of these studies are better than others, but there are at least 13 randomized controlled trials of “cry it out” programs. Mindell JA, Kuhn B, Lewin DS, Meltzer LJ, Sadeh A. Behavioral treatment of bedtime problems and night wakings in infants and young children. Sleep 2006;29(10):1263–76.
4. Kerr SM, Jowett SA, Smith LN. Preventing sleep problems in infants: A randomized controlled trial. J Adv Nurs 1996;24(5):938–42.
5. Hiscock H, Bayer J, Gold L, Hampton A, Ukoumunne OC, Wake M. Improving infant sleep and maternal mental health: A cluster randomised trial. Arch Dis Child 2007;92(11):952–58.
6. Mindell JA et al. Behavioral treatment of bedtime problems and night wakings.
7. Leeson R, Barbour J, Romaniuk D, Warr R. Management of infant sleep problems in a residential unit. Childcare Health Dev 1994;20(2):89–100.
8. Eckerberg, B. Treatment of sleep problems in families with young children: Effects of treatment on family well-being. Acta Pædiatrica 2004;93:126–34.
9. Mindell JA et al. Behavioral treatment of bedtime problems and night wakings.
10. Gradisar M, Jackson K, Spurrier NJ, et al. Behavioral interventions for infant sleep problems: A randomized controlled trial. Pediatrics 2016;137(6).
11. Hiscock H et al. Improving infant sleep and maternal mental health.
12. Price AM, Wake M, Ukoumunne OC, Hiscock H. Five-year follow-up of harms and benefits of behavioral infant sleep intervention: Randomized trial. Pediatrics 2012;130(4):643–51.
13. Blunden SL, Thompson KR, Dawson D. Behavioural sleep treatments and night time crying in infants: Challenging the status quo. Sleep Med Rev 2011;15(5):327–34.
14. Blunden SL et al. Behavioural sleep treatments and night time crying in infants.
15. Middlemiss W, Granger DA, Goldberg WA, Nathans L. Asynchrony of mother-infant hypothalamic-pituitary-adrenal axis activity following extinction of infant crying responses induced during the transition to sleep. Early Hum Dev 2012;88(4):227–32.
16. Kuhn BR, Elliott AJ. Treatment efficacy in behavioral pediatric sleep medicine. J Psychosom Res 2003;54(6):587–97.
CHAPTER 12: BEYOND THE BOOBS: INTRODUCING SOLID FOOD
1. Du Toit G, Katz Y, Sasieni P, et al. Early consumption of peanuts in infancy is associated with a low prevalence of peanut allergy. J Allergy Clin Immunol 2008;122(5):984–91.
2. Du Toit G, Roberts G, Sayre PH, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med 2015;372(9):803–13.
3. For a discussion of updated and older guidelines, see Togias A, Cooper SF, Acebal ML, et al. Addendum guidelines for the prevention of peanut allergy in the United States: Report of the National Institute of Allergy and Infectious Diseases–sponsored expert panel. J Allergy Clin Immunol 2017;139(1):29–44.
4. Brown A, Jones SW, Rowan H. Baby-led weaning: The evidence to date. Curr Nutr Rep 2017;6(2): 148–56.
5. Taylor RW, Williams SM, Fangupo LJ, et al. Effect of a baby-led approach to complementary feeding on infant growth and overweight: A randomized clinical trial. JAMA Pediatr 2017;171(9):838–46.
6. Moorcroft KE, Marshall JL, Mccormick FM. Association between timing of introducing solid foods and obesity in infancy and childhood: A systematic review. Matern Child Nutr 2011;7(1):3–26.
7. Rose CM, Birch LL, Savage JS. Dietary patterns in infancy are associated with child diet and weight outcomes at 6 years. Int J Obes (Lond) 2017;41(5):783–88.
8. Mennella JA, Trabulsi JC. Complementary foods and flavor experiences: Setting the foundation. Ann Nutr Metab 2012;60 (Suppl 2):40–50.
9. Mennella JA, Nicklaus S, Jagolino AL, Yourshaw LM. Variety is the spice of life: Strategies for promoting fruit and vegetable acceptance during infancy. Physiol Behav 2008;94(1):29–38. Mennella JA, Trabulsi JC. Complementary foods and flavor experiences.
10. Atkin D. The caloric costs of culture: Evidence from Indian migrants. Amer Econ Rev 2016;106(4): 1144–81.
11. Leung AK, Marchand V, Sauve RS. The “picky eater”: The toddler or preschooler who does not eat. Paediatr Child Health 2012;17(8):455–60.
12. Fries LR, Martin N, Van der Horst K. Parent-child mealtime interactions associated with toddlers’ refusals of novel and familiar foods. Physiol Behav 2017;176:93–100.
13. Birch LL, Fisher JO. Development of eating behaviors among children and adolescents. Pediatrics 1998;101(3 Pt 2):539–49. Lafraire J, Rioux C, Giboreau A, Picard D. Food rejections in children: Cognitive and social/environmental factors involved in food neophobia and picky/fussy eating behavior. Appetite 2016;96:347–57.
14. Perkin MR, Logan K, Tseng A, Raji B, Ayis S, Peacock J, et al. Randomized trial of introduction of allergenic foods in breast-fed infants. N Engl J Med 2016;374(18):1733–43. Natsume O, Kabashima S, Nakazato J, Yamamoto-Hanada K, Narita M, Kondo M, et al. Two-step egg introduction for prevention of egg allergy in high-risk infants with eczema (PETIT): A randomised, double-blind, placebo-controlled trial. Lancet 2017;389(10066):276–86. Katz Y, Rajuan N, Goldberg MR, Eisenberg E, Heyman E, Cohen A, Leshno M. Early exposure to cow’s milk protein is protective against IgE-mediated cow’s milk protein allergy. J Allergy Clin Immunol 2010;126(1):77–82.
15. Hopkins D, Emmett P, Steer C, Rogers I, Noble S, Emond A. Infant feeding in the second 6 months of life related to iron status: An observational study. Arch Dis Child 2007;92(10):850–54.
16. Pegram PS, Stone SM. Botulism. UpToDate. Accessed 2017. Available at http://www.uptodate.com/contents/botulism.
17. Emmerson AJB, Dockery KE, Mughal MZ, Roberts SA, Tower CL, Berry JL. Vitamin D status of white pregnant women and infants at birth and 4 months in North West England: A cohort study. Matern Child Nutr 2018;14(1).
18. Greer FR, Marshall S. Bone mineral content, serum vitamin D metabolite concentrations, and ultraviolet B light exposure in infants fed human milk with and without vitamin D2 supplements. J Pediatr 1989;114(2):204–12. Naik P, Faridi MMA, Batra P, Madhu SV. Oral supplementation of parturient mothers with vitamin D and its effect on 25OHD status of exclusively breastfed infants at 6 months of age: A double-blind randomized placebo controlled trial. Breastfeed Med 2017;12(10):621–28.
19. Naik P et al. Oral supplementation of parturient mothers with vitamin D. Thiele DK, Ralph J, El-Masri M, Anderson CM. Vitamin D3 supplementation during pregnancy and lactation improves vitamin D status of the mother-infant dyad. J Obstet Gynecol Neonatal Nurs 2017;46(1):135–47.
CHAPTER 13: EARLY WALKING, LATE WALKING: PHYSICAL MILESTONES
1. Serdarevic F, Van Batenburg-Eddes T, Mous SE, et al. Relation of infant motor development with nonverbal intelligence, language comprehension and neuropsychological functioning in childhood: A population-based study. Dev Sci 2016;19(5):790–802.
2. Murray GK, Jones PB, Kuh D, Richards M. Infant developmental milestones and subsequent cognitive function. Ann Neurol 2007;62(2):128–36.
3. Much of the discussion here comes from Voigt RG. Developmental and behavioral pediatrics. Eds. Macias MM and Myers SM. American Academy of Pediatrics, 2011.
4. Barkoudah E, Glader L. Epidemiology, etiology and prevention of cerebral palsy. UpToDate. Accessed 2018. Available at https://www.uptodate.com.revproxy.brown.edu/contents/epidemiology-etiology-and-prevention-of-cerebral-palsy [inactive].
5. WHO Motor Development Study: Windows of achievement for six gross motor development milestones. Acta Paediatr Suppl 2006;450:86–95.
6. WHO Motor Development Study.
7. Pappas D. The common cold in children: Clinical features and diagnosis. UpToDate. Accessed 2018. Available at https://www.uptodate.com/contents/the-common-cold-in-children-clinical-features-and-diagnosis.
8. Pappas D. The common cold in children.
9. Klein J, Pelton S. Acute otitis media in children: Epidemiology, microbiology, clinical manifestations, and complications. UpToDate. Accessed 2018. Available at https://www.uptodate.com/contents/acute-otitis-media-in-children-epidemiology-microbiology-clinical-manifestations-and-complications.
CHAPTER 14: BABY EINSTEIN VS. THE TV HABIT
1. Barr R, Hayne H. Developmental changes in imitation from television during infancy. Child Dev 1999;70(5):1067–81.
2. Kuhl PK, Tsao FM, Liu HM. Foreign-language experience in infancy: Effects of short-term exposure and social interaction on phonetic learning. Proc Natl Acad Sci USA 2003;100(15):9096–101.
3. DeLoache JS, Chiong C. Babies and baby media. Am Behav Scientist 2009;52(8):1115–35.
4. Robb MB, Richert RA, Wartella EA. Just a talking book? Word learning from watching baby videos. Br J Dev Psychol 2009;27(Pt 1):27–45.
5. Richert RA, Robb MB, Fender JG, Wartella E. Word learning from baby videos. Arch Pediatr Adolesc Med 2010;164(5):432–37.
6. Rice ML, Woodsmall L. Lessons from television: Children’s word learning when viewing. Child Dev 1988;59(2):420–29.
7. Bogatz GA, Ball S. The Second Year of Sesame Street: A Continuing Evaluation, vol. 1. Princeton, NJ: Educational Testing Service, 1971.
8. Kearney MS, Levine PB. Early childhood education by MOOC: Lessons from Sesame Street. Natl Bureau Econ Res working paper no. 21229, June 2016.
9. Nathanson AI, Aladé F, Sharp ML, Rasmussen EE, Christy K. The relation between television exposure and executive function among preschoolers. Dev Psychol 2014;50(5):1497–506.
10. Crespo CJ, Smit E, Troiano RP, Bartlett SJ, Macera CA, Andersen RE. Television watching, energy intake, and obesity in US children: Results from the third National Health and Nutrition Examination Survey, 1988–1994. Arch Pediatr Adolesc M
ed 2001;155(3):360–65.
11. Zimmerman FJ, Christakis DA. Children’s television viewing and cognitive outcomes: A longitudinal analysis of national data. Arch Pediatr Adolesc Med 2005;159(7):619–25.
12. Gentzkow M, Shapiro JM. Preschool television viewing and adolescent test scores: Historical evidence from the Coleman Study. Quart J Econ 2008;123(1):279–323.
13. Handheld screen time linked with speech delays in young children. Abstract presented at American Academy of Pediatrics, PAS meeting, 2017.
CHAPTER 15: SLOW TALKING, FAST TALKING: LANGUAGE DEVELOPMENT
1. Nelson K. Narratives from the Crib. Cambridge, MA: Harvard University Press, 2006.
2. “The MacArthur-Bates Communicative Development Inventory: Words and sentences.” https://www.region10.org/r10website/assets/File/Mac%20WS_English.pdf [inactive].
3. Available at http://wordbank.stanford.edu/analyses?name=vocab_norms.
4. Rescorla L, Bascome A, Lampard J, Feeny N. Conversational patterns and later talkers at age three. Appl Psycholinguist 2001;22:235–51.
5. Rescorla L. Age 17 language and reading outcomes in late-talking toddlers: Support for a dimensional perspective on language delay. J Speech Lang Hear Res 2009;52(1):16–30. Rescorla L. Language and reading outcomes to age 9 in late-talking toddlers. J Speech Lang Hear Res 2002;45(2):360–71. Rescorla L, Roberts J, Dahlsgaard K. Late talkers at 2: Outcome at age 3. J Speech Lang Hear Res 1997;40(3):556–66.
6. Hammer CS, Morgan P, Farkas G, Hillemeier M, Bitetti D, Maczuga S. Late talkers: A population-based study of risk factors and school readiness consequences. J Speech Lang Hear Res 2017;60(3): 607–26.
7. Lee J. Size matters: Early vocabulary as a predictor of language and literacy competence. Appl Psycholinguist 2011;32(1):69–92.
8. This graph was created by generating some example data based on the mean and standard deviations provided in the paper.