Co-sleeping is one of those parenting topics that can spark strong opinions—some swear by it, others avoid it completely. In many parts of the world, it’s totally normal for families to share a sleeping space for years. In the West, though, we tend to approach it with more hesitation.
But when you dig into the research, especially a 2019 article by Elaine S. Barry titled “Co-sleeping as a proximal context for infant development: The importance of physical touch”, a different picture begins to emerge. Barry presents co-sleeping not as just a cultural preference, but as something biologically wired into our babies, especially in their first year.
This post breaks down her research and offers some clarity around the developmental role of co-sleeping, and when it may no longer be needed.
Why Physical Touch at Night Matters
Barry’s article draws from neuroscience, developmental psychology, and anthropology to argue that co-sleeping offers more than convenience, it offers essential regulatory support to newborns, who are still developing the ability to manage stress, body temperature, and even emotional stability.
In other words, your baby’s brain and body expect to be near you, especially at night. Physical closeness isn’t just comforting, it’s developmental.
Here are some of the major takeaways:
- Gentle touch during infancy plays a key role in shaping a baby’s sense of body awareness and emotional connection (Field, 2010).
- Being physically close also helps regulate a baby’s stress system by lowering cortisol levels and building resilience over time (Hofer, 2006).
- When parents and babies sleep near each other, their heart rates, breathing, and sleep rhythms often sync up in a way that strengthens emotional bonding and security (Feldman, 2007).
- Over time, that kind of regular nighttime closeness helps build the parts of a baby’s brain responsible for emotional regulation and self-soothing later in life (Schore, 2001).
So, When Is It Time to Transition?
Barry doesn’t give a strict age because every baby is different. But the research she references points to the first 6–12 months as the most sensitive time for the benefits of nighttime physical closeness.
During this window, babies lean heavily on your presence to regulate their systems. Around the one-year mark, many babies start developing more independence and the ability to self-soothe, which makes transitioning to their own sleep space more appropriate.
That transition can happen gradually, anytime between 9 and 18 months, depending on your child’s temperament, family routine, and comfort level.
Disclaimer
It’s important to mention why Western pediatricians, including the American Academy of Pediatrics (AAP), often advise against bed-sharing. Their main concern is safety, particularly around SIDS (Sudden Infant Death Syndrome)and accidental suffocation.
The AAP recommends room-sharing (baby in the same room, but not the same bed) for at least the first six months, and ideally up to a year. If you choose to co-sleep, be sure your sleep setup follows these safety guidelines:
- Baby is on a firm, flat surface (no pillows or soft bedding)
- No one in the bed smokes or has used alcohol/sedatives
- Baby isn’t sleeping between adults or on a couch/armchair
Done safely, co-sleeping can offer incredible developmental benefits. But safety always has to come first.
Lastly,
Every family is different. What matters most is that your sleep setup—whatever that may look like—supports your baby’s development, your family’s well-being, and your peace of mind.
Co-sleeping can absolutely be a beautiful, biologically attuned part of early parenting, especially in that first precious year. Barry’s research helped me understand why it feels so natural and when it might be time to gently shift toward independent sleep.
I’ve been struggling to transition my 8-month-old to her crib. Watching her on the monitor, I’d find myself missing her and just wanting to be close. Reading the research gave me peace of mind; it reminded me that this longing for physical closeness is completely normal. We’re still gently working on the transition—but we’re not rushing or forcing it.
Trust your gut, stay informed, and make the decision that’s right for your family.
References
Barry, E.S. (2019). Co-sleeping as a proximal context for infant development: The importance of physical touch. Infant Behavior and Development, 57, 101385. Link
Hofer, M.A. (2006). Psychobiological roots of early attachment. Current Directions in Psychological Science, 15(2), 84–88.
Feldman, R. (2007). Parent-infant synchrony. Current Directions in Psychological Science, 16(6), 340–345.
Field, T. (2010). Touch for socioemotional and physical well-being. Developmental Review, 30(4), 367–383.
Schore, A.N. (2001). Effects of a secure attachment relationship on right brain development. Infant Mental Health Journal, 22(1–2), 7–66.
American Academy of Pediatrics (2022). Safe Sleep Recommendations. www.aap.org