Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool

“Circumcision is an optional procedure. It’s not common everywhere—for example, Europeans typically do not circumcise. It has historically been quite common in the US, although circumcision rates have declined some over time, from an estimated 65 percent of births in 1979 to 58 percent in 2010.”

Oster discusses the elective nature of circumcision, and sheds light on its cultural variability and historical prevalence. Oster underscores the regional distinctions, noting that while circumcision is not a common practice in Europe, it has historically been prevalent in the United States. The mention of a decline in circumcision rates from 65% in 1979 to 58% in 2010 suggests a shifting trend. Oster’s advocates for a structured decision-making process that involves weighing the medical, cultural, and personal aspects of circumcision, aligning with the overarching theme of The Value of Data in Parenting.

“You’ll also sometimes see swaddling discussed in connection with an increased risk of sudden infant death syndrome (SIDS). To the extent we have data, this concern does not seem valid, as long as you are putting the baby to sleep on its back (which you should do regardless). Infants who are put to sleep on their stomach and are swaddled are at an increased risk of SIDS relative to those put to sleep on their stomach alone.”

Oster addresses the controversial topic of swaddling in connection with the risk of SIDS. Oster refers to the existing data to debunk concerns related to swaddling and its association with SIDS, emphasizing that the critical factor in SIDS prevention is placing the baby to sleep on its back, a practice widely recommended. She emphasizes that the combination of placing infants on their stomach and swaddling increases the risk of SIDS. Oster’s analysis contributes to dispelling potential anxieties surrounding swaddling and provides a rational perspective on a parenting practice that often sparks debates and concerns.

“For people who love data, there is a seduction to seeing the numbers there in black and white. You can look for patterns—on one day, the baby slept for seven hours. Why was that? Was it the twenty-three minutes of nursing before? Should you try exactly that length of time again?”

Oster delves into the allure that data holds for individuals who have an inclination toward analytical thinking. Data offers the promise of clear answers in what is often a confusing experience. The questioning of whether the duration of nursing correlates with the baby’s extended sleep highlights the curiosity and analytical mindset of parents seeking patterns in their child’s behavior.

“The American College of Obstetricians and Gynecologists says that it is safe to resume exercise ‘within a few days’ after a normal vaginal delivery. This isn’t to say you will be running interval workouts a week later, but some walking may be feasible.”

Oster conveys the importance of acknowledging individual recovery variations—noting that both “exercise” and “a few days” are relative terms. The advice fosters a realistic approach to postpartum recovery, ensuring that readers are aware of the timeline involved in resuming physical activities after childbirth. Oster consistently relies on expert guidance to substantiate her insights, which contributes to the credibility of her data-driven parenting approach.

“Looking at the data—which, in this case, may not be so helpful, since really the question is when you want to do it—most couples have resumed at least some sexual activity by eight weeks postpartum. For those with an uncomplicated vaginal delivery, the average is about five weeks, versus six weeks for caesarean and seven for those with significant vaginal tearing.”

The author addresses the complex and often emotionally charged topic of postpartum sexual activity. By presenting data on the average timeline for resuming sexual activity after childbirth, Oster takes a pragmatic approach, acknowledging the diversity in individual experiences. The phrase “which, in this case, may not be so helpful, since really the question is when you want to do it,” reflects Oster’s recurrent theme of contextual decision-making. She not only provides statistical information but also underscores the importance of personal preferences and readiness in the postpartum journey.

“Some of the questions here seem so obvious that it can be hard to imagine you’d actually need a questionnaire—can’t you just ask people if they feel sad and disengaged? But the evidence suggests that using this screening tool can be extremely effective. Researchers have shown improvements in detection (and therefore treatment) of postpartum depression across a large number of women by using this questionnaire—as much as a 60 percent reduction in depression a few months later.”

Oster delves into the effectiveness of using a questionnaire as a screening tool for postpartum depression. She highlights the seemingly straightforward nature of questions about emotions but emphasizes the substantial impact such a tool can have on detection and subsequent treatment. Oster’s analytical tone suggests a reliance on empirical evidence, aligning with her overall approach. By citing research findings that indicate up to a 60% reduction in depression a few months later, Oster underscores the practical significance of implementing structured assessments.

“The pressure on moms to breastfeed can be immense. The rhetoric makes it seem like this is the most important thing you can—and need—to do to set your child up for success. Breastfeeding is magic! Milk is liquid gold!”

Oster critically examines the societal pressure on mothers to breastfeed and the hyperbolic rhetoric surrounding it. By using phrases like “immense pressure” and “rhetoric,” Oster explores the cultural expectations placed on mothers regarding breastfeeding. The choice of words such as “magic” and “liquid gold” highlights the idealization and sometimes unrealistic portrayal of breastfeeding benefits. Oster seems to challenge these exaggerated claims, and sets the stage for a more evidence-based discussion about breastfeeding.

“People wrote of feeling isolated and falling behind at their jobs because of the hours they spent shut in their offices pumping, of the embarrassment of asking for pumping time on business trips, or pumping in the bathroom since there was no other place to do it. And they told of the frustration of not getting enough milk, even with all their effort.”

Oster delves into the challenges faced by working mothers who choose to breastfeed, shedding light on the emotional and practical hurdles associated with pumping breast milk in professional settings. Phrases such as “feeling isolated,” “falling behind at their jobs,” and “embarrassment” underscore the often-overlooked struggles that working mothers encounter in trying to balance career demands with the commitment to breastfeeding. Oster presents real-life experiences and fosters a more open and honest conversation about the complexities of navigating parenting choices and challenges.

“Across virtually all studies of sleep location, the one thing that jumps out as really, really risky is babies sharing a sofa with an adult. Death rates as a result of this behavior are twenty to sixty times higher than the baseline risk. It is not difficult to see why: an exhausted adult falls asleep holding an infant on a cushiony sofa, and it is easy for the infant to be smothered by a pillow.”

Here, the author delves into the critical topic of sleep location for infants, highlighting the significant risks associated with babies sharing a sofa with an adult. The use of quantitative data, such as “twenty to sixty times higher than the baseline risk,” adds a layer of urgency, and compels readers to recognize the potential dangers involved in this specific sleep arrangement. Oster employs straightforward language to paint a vivid picture of the scenario: an exhausted adult falling asleep with an infant on a soft sofa, highlighting the ease with which a tragic accident, such as smothering, can occur.

“How much sleep is enough, and when should it happen? It seems like a simple question, but answers differ widely. Take, for example, the two category-killer sleep books: Ferber (Solve Your Child’s Sleep Problems) and Weissbluth (Healthy Sleep Habits, Happy Child). Both provide some guidance on the amount you should expect your child to sleep. The trouble is, they do not agree.”

Oster addresses common parenting anxiety related to infant sleep and refers to the conflicting advice provided by renowned sleep experts Ferber and Weissbluth. The use of the term “category-killer sleep books” employs a touch of figurative language, suggesting these books as authoritative and influential in the domain of sleep advice. Oster underscores the paradoxical nature of parenting guidance by juxtaposing the recommendations of two prominent experts, Ferber and Weissbluth, and reveals the lack of consensus in the field.

“The scientific consensus on vaccinations is extremely clear: vaccines are safe and effective. This conclusion is supported by a very wide range of doctors and medical organizations, and by government and non-government entities. But despite this, there are parents who choose not to vaccinate, and many of them are well educated and have thought about the decision.”

The author uses the phrase “scientific consensus” as a rhetorical device to underline the overwhelming agreement within the scientific community on the benefits of vaccinations. Oster acknowledges the paradoxical situation where, despite the clarity of scientific evidence, some well-educated parents opt not to vaccinate. This observation challenges the assumption that vaccine hesitancy is solely rooted in a lack of information or education. Oster refers to a common phenomenon of vaccine skepticism, highlighting both The Value of Data in Parenting and the difficulties of Navigating Changing Guidelines.

“Parental leave appears to be beneficial. There is a growing body of evidence suggesting that babies do better when their mothers take some maternity leave. In the US, for example, research has shown that when the FMLA was introduced, babies did better. Premature birth went down, as did infant mortality.”

Oster delves into the positive impact of parental leave on infant well-being. She highlights a growing body of evidence indicating that babies benefit when their mothers take time off work after childbirth. Drawing on research in the United States, Oster notes that the introduction of the Family and Medical Leave Act (FMLA) resulted in improved outcomes for infants, including a reduction in premature births and infant mortality. Oster employs empirical data and legislative changes to reinforce the notion that parental leave contributes to positive health outcomes for infants, and highlights the broader societal implications of supportive leave policies.

“The choice of childcare doesn’t have to be either-or. Looking over the data, to the extent we have any evidence day care is worse, it seems to be worse early on in life—say, in the first year or eighteen months. To the extent day care is better, that seems to be truer later in life—say, after a year or eighteen months. Putting this together could argue for a nanny-type arrangement (or a helpful grandparent, or some combination of the two) early on, followed by day care at a slightly older age.”

The author challenges the common either-or assumption regarding the choice between daycare and other childcare arrangements. Through a careful examination of the available evidence, Oster suggests that, if any negative impact of daycare exists, it may be more pronounced in the early stages of a child’s life, within the first year or 18 months. Conversely, she hints that daycare might offer advantages later in a child’s development. Oster’s approach is pragmatic, and proposes a flexible solution—a nanny or supportive grandparent in the early months, transitioning to daycare as the child grows older. This evidence-based exploration empowers parents to take into account developmental stages and the potential benefits of varied arrangements.

“When we were going through this with Finn the first night, he was crying and we were finishing putting Penelope to bed. I was anxious—no matter how convinced you are of the plan; it is very hard to listen to your baby cry. Penelope looked at me—very seriously—and told me, Mom, whatever you do, you can’t go in. He needs to learn to sleep on his own. We have to help him do that.”

Oster shares a personal experience to refer to the challenges of implementing a sleep training plan. Through the narrative of her daughter Penelope advising her not to intervene while her baby brother Finn was crying, Oster delves into the emotional struggle parents face when attempting sleep training. Oster underscores the difficulty of resisting the instinct to comfort a crying baby, and emphasizes the importance of consistency in sleep training. This personal anecdote adds depth to Oster’s evidence-based approach by incorporating the emotional dimensions of parenting.

“There is some debate about the right time to introduce solid foods and, in particular, a question of whether introducing solids too early will lead to obesity later. What is the reason to wait for four months at all? Should you really be waiting for six months, or longer? The reasons to wait until four months are largely physiological—babies really cannot eat before this—but waiting longer than that doesn’t seem like it matters. There is some correlation between the timing of food introduction and childhood obesity, but it seems to be due to other factors, like parental weight and diet.”

Oster’s approach demystifies common anxieties around introducing solid foods. While babies are not typically ready for solid foods prior to four months, the fear that fear that introducing solid food too early will lead to obesity is largely unfounded. As she does throughout the book, Oster provides parents with a scientifically grounded perspective to inform their decision-making while puncturing the fear that any one decision will have drastic consequences.

. “There is simply nothing in the data that would make us think that earlier walking or standing or rolling or head raising is associated with any later outcomes. Looking for delays is a good idea; looking for exceptionalism, or worrying about a child who is at the end of the normal range, is probably not.”

Oster addresses common anxieties about the timing of developmental milestones such as walking, standing, rolling, and head raising. By referring to the existing data, she dismisses the notion that earlier achievement of these milestones correlates with better long-term outcomes. Oster encourages a pragmatic approach by suggesting that focusing on identifying delays is a reasonable concern, while obsessing about a child at the end of the normal range may be unwarranted. This analysis underscores Oster’s commitment to grounding parental decisions in empirical evidence, alleviating some of The Anxiety of Parenting Very Young Children, and providing a more informed perspective on child development.

“Our intuitions should be informed by the economic idea of ‘opportunity cost of time.’ If a child is watching TV, they are not doing something else. Depending on what that ‘something else’ is, TV watching may be better or worse. Many studies of this emphasize that (for example) your kid can learn letters or vocabulary from Sesame Street, but they are better at learning those things from you. That’s almost certainly true, but it is less obvious to me that this is the alternative. Many parents use TV to take a break, get their breath, make a meal, do some laundry. If the alternative to an hour of TV is a frantic and unhappy parent yelling at their kid for an hour, there is good reason to think the TV might actually be better.”

Oster introduces the economic concept of the “opportunity cost of time” to assess the impact of children watching TV. By framing the discussion around what children could be doing instead, she emphasizes the multifaceted nature of the decision. Oster acknowledges the potential educational benefits of programs like Sesame Street but highlights the importance of considering the context. By introducing the idea that the alternative to TV might be a stressed and unhappy parent, Oster challenges conventional notions and encourages a more holistic perspective on the decision regarding screen time based on an individual’s circumstances.

“And if you are really curious, it’s definitely possible to use the data here to do some more concrete comparisons. But it is crucial to keep in mind that the predictive ability of early language, while there, is really quite poor. Early talking doesn’t guarantee later success—even at four—and late talkers mostly look like everyone else within a few years.”

Oster, in discussing the predictive ability of early language development, urges caution against overestimating its significance in determining later success. Oster encourages readers to approach the data with a critical mindset, highlighting the complexity of factors that contribute to a child’s overall development and success. This analysis underscores Oster’s commitment to providing an evidence-based perspective on parenting decisions, steering readers away from simplistic correlations between early behaviors and future outcomes.

“There is no evidence linking age of potty training with any later outcomes like IQ or education. So if your child is trained early, that might be great (for you) but irrelevant in the long term.”

Oster debunks the myth that early potty training has any meaningful impact on later outcomes such as IQ or education. By presenting the lack of evidence supporting a connection between the timing of potty training and future cognitive or educational achievements, Oster reassures parents that the challenges and efforts involved in the toilet training process are unlikely to have a lasting impact on a child’s intellectual development. This analysis reflects Oster’s commitment to assuaging The Anxiety of Parenting Very Young Children.

“Kids can be frustrating and, yes, they do need to be punished sometimes. But this punishment should be part of a system of discipline that aims to teach them how to be productive adults. Learning that if you misbehave you’ll lose some privileges or some fun experience is something that will serve you well as an adult. Kids do not need to learn that if you misbehave, a stronger person will hit you.”

By emphasizing the importance of a disciplinary system focused on teaching children how to become productive adults, Oster rejects the notion that physical punishment is an effective method of instilling discipline. Her analysis aligns with contemporary parenting research that highlight the significance of positive reinforcement rather than resorting to punitive measures. This perspective contributes to the broader theme in Oster’s work of challenging conventional wisdom and encouraging parents to make decisions grounded in evidence and a thoughtful understanding of child development.

“Finally, to the extent that your child does go to preschool in this age range, does it matter what kind of preschool it is? We’ve already been over the importance of quality in the chapter on day care, but beyond having loving teachers and a safe environment, should you care about the philosophy of the program, or even whether it has one?”

Oster extends the discussion of early childhood education and questions whether the philosophical orientation of a preschool program should be a significant consideration for parents. Oster recognizes the importance of fundamental factors such as having caring teachers and a safe environment, as previously emphasized in the chapter on day care. Oster’s approach involves not only practical considerations but a deeper exploration of how a preschool’s guiding principles may impact a child’s learning experience.

“Some small-scale randomized interventions do show some effectiveness. One is the ‘marriage checkup.’ The idea behind this is to have an annual meeting—possibly facilitated by some professional—to actually discuss your marriage. What do you feel is working? What isn’t working? Are there particular areas of concern or unhappiness? These checkups seem to result in improvements in intimacy (i.e., sex) and marital satisfaction. This makes sense in the abstract; it’s helpful to talk things through methodically with a neutral third party.”

Oster introduces the concept of a “marriage checkup” as a potential solution to maintaining and enhancing marital satisfaction after having children. The idea is to engage in a thoughtful and methodical conversation with a neutral third party, which, according to Oster, can lead to improvements in intimacy and overall marital satisfaction. By advocating for regular check-ins and open communication, Oster emphasizes the importance of addressing marital challenges proactively, especially in the context of the added stressors that come with parenting.

“Again, this is hard to study, given the differences across families. To the extent that we have evidence, this concern seems unfounded. One review article, which summarizes 140 studies on this broad question, found some evidence of more ‘academic motivation’ among only children, but no differences in personality traits like extroversion. Even this fact about academic motivation may be more about birth order—firstborn children score higher on this regardless of whether they have siblings—than about being an only child.”

Oster addresses the common concern and stereotypes surrounding only children, highlighting the challenges in studying this topic due to the inherent differences across families. Oster refers to a review article to challenge the notion that being an only child is associated with negative outcomes. She notes that while there is some evidence suggesting increased “academic motivation” among only children, this might be influenced by birth order, as firstborn children tend to exhibit higher academic motivation irrespective of the number of siblings. Oster’s analysis encourages readers to critically assess preconceived notions and stereotypes about family dynamics and their impact on children’s development.