Why We Don’t Walk at Birth

Scientists have figured out why human babies can’t walk at birth, while foals and other hoofed animals get up and go within hours of being born.

Scientists have figured out why human babies can’t walk at birth, while foals and other hoofed animals get up and go within hours of being born. It seems that all mammals take their first steps at the same point in brain development. A team of Swedish scientists has come up with a model that can predict the onset of those first steps with information on the weight of that animal’s mature brain (which indicates brain development time) and whether the species stands with its heels touching the ground like us or on its toes like cats and horses. So while humans might not walk until just under one year of age and an elephant in just a day, both organisms hit this milestone at the same point in their brain development. The scientists looked at the relationship between brain size and limb biomechanics, and the onset of walking for 24 mammal species, from conception stage. For humans, that would add about nine months to this walking clock. There was a pattern that could mostly be explained by differences in brain mass.