Skip to main content

The Neuroscience of Paid Parental Leave

Having parents present is crucial during an infant’s first weeks of development—but institutions that train physicians don’t always seem to care

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


As a new father, I’ve learned that the U.S. ranks at the very bottom of industrialized nations for paid parental leave. Denmark offers a year. Italy offers five months. France offers 16 weeks; Mexico, 12 weeks; Afghanistan, 13. According to a 2016 Pew Research Center analysis of 41 countries, the U.S. is the only one to offer zero paid parental leave.

It is easy (and likely accurate) to assume that paid parental leave policies are a nice gesture to help exhausted, stressed-out parents have the time and resources to figure out how to care for an infant. Perhaps this is why it is often bundled with leaves for tending to a sick family member. But the focus should be more directly on the infants themselves, with parental leave being a necessary measure to ensure infant health during a critical period of brain development.

THE NEUROSCIENCE OF PARENTAL LEAVE


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


What happens to the infant shortly after birth drastically alters his or her brain. Postnatal brain maturation is enormous in scope. Each day, tens of thousands of new synapses are formed. Genetic programs guide the birth of these synapses, but what signals the infant’s brain receives from the eyes, ears, skin and other senses sculpt how the brain’s functional anatomy is ultimately organized and implemented. Frequently used synapses form stronger, more efficient connections that coalesce into networks. Unused synapses die off. This is not an example of “use it or lose it,” but rather “use it or it never will be.”

The visual system, for example, simply cannot form in the absence of visual input. Ocular dominance columns, the neural centers in the visual cortex that process binocular vision, require visual stimulation from both eyes within a critical period, which is why infant cataracts are aggressively and quickly treated. Emotion and cognitive systems also do not form properly in the absence of specific inputs. Here, a parent’s caress, the melody of a mother’s voice, the smell of a father’s chest is incarnated, engineered into the cognitive foundation that the infant will use to make sense of the world. Brain development is why the parent-child relationship is so important—you can keep an infant warm and nourished without it, but their brain won’t develop properly.

Attachment describes what the infants’ brains infer about their parents and how children should behave to get what they need. When parents are consistently present and respond to distress promptly and with reassurance, infants infer a secure and organized attachment. Behaviorally, infants learn that they can express negative emotions and this will bring about comfort from their parents. When parents are not present or become annoyed, ignore or ridicule their needs, infants infer an insecure attachment and organize behaviors that avoid parents in times of need or display extreme negative emotion to draw attention to the inconsistently responsive parent.

Attachment is a powerful predictor of a child’s social and emotional growth. As the infant’s foundational experience with the world, the relationship with parents predicts later relationships and interactions. During this time of drastic synaptic remodeling, a poor attachment leaves a devastating mark on the infant’s sensitive brain. Studies have shown that Romanian orphans who were reared in extreme physical and social isolation have smaller brains and, as a result, are more likely to suffer mental health issues in peri-adolescence. Adopted orphans from Romania and China have a larger amygdala than their non-adopted counterparts, suggesting grossly and irreversibly altered emotion and fear processing networks.

Paid parental leave (for both parents) is associated with decreased infant mortality, less postpartum depression, more breastfeeding, more follow-up doctor appointments and more involved dads—all things that promote healthy brain development.

STATE OF THE RESIDENCIES: PHYSICIANS, HEAL THYSELVES

As a physician trainee and a dad, I’ve been surprised that resident leave policies are ironically inconsistent with knowledge of brain development and what the medical profession itself recommends.

In 2013 the American Academy of Pediatrics released a policy statement “Parental Leave for Residents and Pediatric Training Programs” that emphasized “the AAP recommends that regardless of gender, residents who become parents should be guaranteed six to eight weeks, at a minimum, of parental leave with pay after the infant’s birth.” As a resident, Yale allowed me two weeks of paid leave because I am a man fathering a child. Surprisingly, Yale offers six weeks to men adopting a child and six weeks to women either mothering or adopting a child. While this policy is not equitable or universal (infants of men fathering a child get shortchanged), Yale’s meager leave is sadly among the better for physician trainees.

Demand for parental leave clearly exists: a recent study published in Academic Medicine reported that among fathers in residency training, 89 percent cited parental leave as an important benefit. From delivery through the first months of brain development, studies have shown that a father’s presence has a strong impact on child development and attachment behaviors.

Nearly half of male residents, and over a third of female residents are parents. If we estimate that there are over 100,000 residents in the U.S., we can expect at least 25,000 pregnancies (half of residents are women, and more than half will have babies during residency) over the course of their around four-year training, or roughly 6,250 pregnancies each year. Those 6,250 little brains need to form secure attachment. And yet parental leave policies remain inconsistent with our own evidence-based recommendations.

AMERICAN MED-CHISMO

Anyone willing to pursue over a decade of postgraduate training to care for strangers in the middle of the night might want more than a few days to welcome their child into the world. At the end of our residencies my wife (also a psychiatry resident) and I will have a combined 27 years of post–high school education (she, 12; me, 15) and four postgraduate degrees in the medical sciences. So why don’t highly skilled laborers who work 80-hour weeks in evidence-based medicine not receive an evidence-based parental leave? I think it’s rooted in what I call, “American Med-chismo.”

American Med-chismo could be best understood by a quote from Sir William Osler, one of the founders of Johns Hopkins: “The practice of medicine ... is a life of self-sacrifice and of countless opportunities to comfort and help the weak-hearted, and to raise up those that fall.” No question, it’s an idealistic and lovely sentiment. But recall that at this time (1890s) residents (almost entirely men) resided (literally) in the hospital. This period of social and familial isolation was euphemistically referred to as a “monastic” existence.

To a resident of and for the hospital, duty hours would have been a laughable idea. It was not at all uncommon for physicians to lean on cocaine or morphine as fuel. Forget about paid parental leave.

And the Med-chismo culture persists. Physician trainees are criticized for a lack of dedication when they pursue less time-intensive specialties and lifestyles. For example, JAMA Surgeryreports that women considering motherhood experience “substantial negative bias” because maternity leave is resented. Many hospitals do not offer leave for parents who aren’t giving birth, and an uncompensated burden is placed on colleagues who cover for new parents.

Yet Med-chismo is not without comorbidities. Physician burnout—a nebulous phenomenon that involves emotional exhaustion, cynicism, and dehumanization—is on the rise. Unsurprisingly, it’s associated with lower patient satisfaction, more medical errors, drug and alcohol use among doctors, even suicide. Over half of doctors, and up to 75 percent of residents, experience it, depending on specialty. But the rates aren’t the same for everyone; residents with children have lower rates of burnout and cynicism. Perhaps this is why residents in the U.K. and Europe have more evidence-based paid parental leave policies. Or maybe they just believe the science.