Giving Birth to Babies with Bipedalism

Here’s an interesting fact: the heads of babies when they are born are 102% the size of the human pelvis. It’s the squeezing of the head that allows women to give birth to such giant brained little ones. One of the reasons we have such huge heads has to do with bipedalism – the ability to walk on two legs. This has allowed us to free up our hands that we could now use for making tools and such, rapidly accelerating brain development in early humans.