A baby in a green t shirt is being held by its caregiver, who has brown hair in a ponytail and is wearing a blue sleeveless t shirt.

I thought given how many questions I get about little ones who need to be held a lot that I’d do a deep dive on touch and closeness. There is a wonderful article by Barry, 2019, which I’ll give you a flavour of, but it’s really worth a full read.

If you think about it, humans give birth to the most immature of all the primate babies. Other primates can cling to their mothers – our babies can’t even do that. They are born able to communicate, and they are brilliantly able in many ways, so I don’t want to imply that they are incompetent… but they are utterly dependent on us. They require their adults to keep them close, keep them safe, keep them fed, keep them warm.

Our babies take the longest of all babies to reach full maturity – the human brain is not fully mature until 25 years. Incidentally, this is one reason we have fewer children (on average) than many other mammals – our children are hugely costly to raise to maturity. In today’s world we might think of the financial expense of having children, but there are numerous costs – the emotional, psychological, relational, nutritional costs just as a jumping off point. So there is essentially a trade-off between having fewer children, but pouring more energy and investment into them.

One of the reasons our babies are so costly to raise is that they literally require our physical input to thrive. Their neurological and sensory systems depend on constant biophysiological feedback from their mother (most studies have not explored this with fathers – this isn’t me being ignorant! Shout out to the dads out there crushing it!). So, ever since primates climbed down out of trees and started the slow process over millions of years of evolving into modern humans, our babies’ brains and bodies have expected this constant feedback.

Just because our culture has moved on and modernised, there are some aspects of development that are actually pretty ancient. The infant neurological system needs the protective environment of proximity, bedsharing, holding close and responsive feeding to develop. Keeping infants close at all times has numerous benefits:

  • It helps us to understand our infant
  • It supports bonding and attachment
  • It enables us to read our infant’s cues and act accordingly
  • It helps us keep them safe, by monitoring them and responding to changes and signals they give us even during sleep
  • It manages their temperature
  • It reduces stress and pain
  • It supports optimal growth
  • It stimulates breathing
  • It provides rich multi-sensory input
  • And it stimulates their central nervous system

It may be primitive… but it’s also profound.

But our culture shapes what we perceive to be normal and desirable, and so, depending on where you live, the community you’re part of, your family history and peer influences, you may either perceive these normal human behaviours positively, or millions of years of human evolution may get caught up in western-centric goals of solitary sleep, and infants who require little to no assistance with calming down, growing or sleeping (Medvecova and Ball, 2022).

We have to ask ourselves though, whether this is truly desirable? If our infants expect to be kept close and responded to promptly from an evolutionary point of view, then the mainstream sleep training narrative is essentially pushing back against millions of years of evolution.

Now, I’d be the last person to say you HAVE to keep your little one close at all times, at all costs, or they will not develop properly. There is nuance and subtlety here. It’s not black and white. Human babies cannot help the needs they have, but we also know that their needs are costly. They always have been. Nothing new there. But perhaps in the context of modern western culture, the cost is dialled up by the lack of support and understanding of normal infant behaviour. I say all this though, also knowing two truths – firstly that doing your best, and good enough parenting really is good enough. And secondly, that there are ways to find sustainability. You don’t need to hold your baby skin to skin continuously for their first two years of life! But hopefully knowing the evolutionary background and the importance of close contact <some/most of the time> helps you to understand why they sometimes don’t seem to want to be put down.

Next time your little one is having a cling-on day, remember that you’re growing a nervous system, healthy stress response, and sensory system. Aren’t you clever 🙂

If you’re struggling with your little one’s sleep and you want to learn more about responsive strategies, you may find my 0-18 month sleep guide, my 18-36 month sleep guide or my Responsive Sleep Support Class helpful.