For young children, body-part identification is where science begins. As I like to say, you can’t know how to use ‘em if you don’t know where they is!
Infants begin to discover the parts of their bodies when we play games with them like “I’ve got your nose” and “This Little Piggy.” By the time they’re toddlers, they can identify at least six of the parts of their bodies. By the time children are 7, they know where and what most of their body parts are. Still, many a child has arrived in the early and even upper-elementary grades not knowing his elbow from his shoulder. And that makes a difference, not just from a physical development standpoint (you’re not going to be a confident mover if you feel clumsy in your body!), but also from a cognitive standpoint. Among other things, spatial awareness and directionality are very much a part of reading and writing.