We have seen that the reason why all proper little girls like to play at taking care of dolls is that their mothers, and their grandmothers, and their great-grandmothers, and their great-great-grandmothers, and all other sizes of grandmothers for a thousand generations, and after that for another thousand, and after that nobody knows how many more, have all been taking care of real babies, until anything that looks like a baby has become about the most interesting and precious thing there is. We have seen also that boys learn to throw things easily, and like to throw things because all the while that their many times great-grandmothers have been taking care of the children, their many times great-grandfathers have been throwing spears and javelins at other people’s ancestors, or at things to eat running about on four legs.

Every proper boy likes to hunt and fish and camp out and play Indian because the most of mankind, up to a few centuries ago, have spent their entire time in hunting, fishing, living in huts, and generally playing Indians. Indians themselves, of course, play Indians all the time; and up to the beginning of the Christian era, our own ancestors, living in the wilds of northern Europe, were about as wild as Indians, and did little except play Indians all their lives. Who knows but that, a thousand years from now, after men have been civilized for a long while, and been getting their livings many years standing at benches or sitting at desks, all proper boys will think it great fun to study out of a book indoors? Perhaps they may; but I think it will be a long time first!

Every proper boy, too, when he gets old enough (and that is not so very old) likes to play at games. Now pretty much all these games, when you come to think of it, baseball, cricket, hockey, tennis, golf, I don’t know how many more, all involve hitting a ball with a stick. If we like to throw balls with our hands because our wild forebears threw javelins and spears with theirs, can you not guess at once that the reason why we like to strike balls with sticks is that these same wild forebears had for so many ages been striking things with clubs and swords? We like what our ancestors had to do. If we cannot cut and thrust and hack and throw and strike at wild animals in the chase or at other men in battle, at least we can do it with a ball. So bat and ball are the boy’s dolls. He plays with them for the same excellent reason that his sister plays with hers.

But why does every proper boy like to climb, and every proper girl too, if she has lived in the country and had a proper chance? About the first thing most of us did, as soon as we learned to creep, was to head for the nearest stairs, and try to climb up. When we get a little older, we cannot so much as set eyes on a fence or a shed roof without wanting to be on top of it; while as for trees, who of us, at a certain age, is satisfied until he has been to the top of every tree in the neighborhood. As for climbing mountains, that is one of the greatest games there is. So there is a climbing instinct in us, as well as a throwing instinct and a hit-something-with-a-bat instinct.

Now our wild ancestors who fished and hunted and played Indians for a living probably did not do much climbing. But long before their day we had certain still more ancient ancestors who were only half human and lived in the trees; and long before these, in turn, were still older ancestors who were not human at all, but regular apes who had hands in place of feet, and could climb like monkeys. These spent their lives in the trees; and in memory of them, each of us in turn, before he is quite old enough to play bat and ball games, is possessed to climb like a monkey, and climbs almost as surely and well.

Some people say, too, that the reason why a drowning person throws up his hands (the very worst thing he possibly could do under the circumstances) is that, being quite crazy with fear, he forgets completely his surroundings, remembers only the dim and far off time when the tree-folk escaped danger by climbing up out of the way, and reaches up for an imaginary branch which hasn’t been there these many thousand years. Perhaps this is so; for my part, I believe it is. At any rate, there is the wonderful grip of the new-born babe. Where did he get it if not by climbing trees, or clinging to his mother when she fled with him thru the branches?

Some people say also that the reason why we like to play hide-and-seek is that our ape ancestors, and our half-human ancestors, and our wild ancestors, and our half civilized ancestors, down to considerably after the time when the school histories begin, have spent no small part of their days stealing softly upon their enemies and the wild creatures they were hunting for food, or else hiding all mousey quiet while some enemy or wild beast is hunting after them.

There are a few people even who say that the reason why we like to go in swimming (we do like it, do we not?) is that in some sort of dim way we remember a still more ancient forebear who lived all the time in the water, who in short, was a veritable fish and did nothing else but swim. I don’t believe this myself. Not that we did not have such an ancestor—there doesn’t seem to be much doubt about that. But it all happened so very, very long ago that it doesn’t seem possible that there should be any trace of those days left. Still who can tell?

At any rate, we like to do a vast number of things that our forebears had to do whether they liked them or not; and if you can think of any other reason than this why you like baseball and hide-and-seek and climbing and dolls, I wish you would tell me.