Photo by Richard Kelly Photography
1.: Your previous book, Thumbs, Toes and Tears, helped explain human nature by looking at traits that are unique to humans and then exploring how they came to be. Since that book was written, it’s become increasingly clear that many other species of humans co-existed and competed in the past, and that now all of them are gone, but one. Us. Why have we survived when so many others failed?
Chip Walter: It’s fascinating how that happened because on the surface it really doesn’t make any evolutionary sense. Our direct line of ancestors faced a dilemma more than a million years ago that could have ended them right there and then. Their brains were growing larger AND they had taken to walking upright at the same time. Both adaptations were helpful except for one problem: walking upright narrows the birth canal and that makes it difficult to bring larger brained babies to full term. The solution was to bring the babies into the world prematurely, and extend their childhood longer AFTER birth. You wouldn’t think that bringing increasingly helpless preemies into existence and then lengthening the time it takes for them to have the next generation of children wouldn’t seem to be a very effective survival strategy. Might be smarter to shorten childhood and have more babies faster. If you were a betting ape in those days, you wouldn’t have given our direct ancestors much of chance. But the creativity and inventiveness our uniquely long childhoods make possible are the reasons, ultimately; that we survived when so many others were shown the evolutionary door.
2.: You say that at one point the human race had been whittled down to near extinction, and only a few thousand of us remained. Why? How did we bounce back?
CW: Around 75,000 years ago the genetic evidence indicates we were, at best, down to a few thousand childbearing Homo sapiens. This would mean there were fewer of us than there are wild chimpanzees on Earth right now. The planet was in the grip of a very nasty ice age that had dried out most of Africa. Pockets of Homo sapiens existed in South Africa and maybe a few other locations. Around this time there was also an immense volcanic eruption in Indonesia and the Homo sapiens in Africa were in the path of the ash cloud. (Other human species were not down wind or in the direct path.) Ironically, around the same time you begin to see the first glimmers of human creativity and symbolic thinking which is necessary for things like art, sculpture and language. Those extra skills apparently helped us bounce back, generate newer, better survival strategies and share innovative ideas.
3.: You have a chapter in the book entitled “The Moral Primate." You point out that most other animals aren’t, don’t worry about being fair, but we struggle with good and evil all the time. Where does our sense of morality come from?
CW: One of the outcomes of a longer childhood for us was that our ancestors found themselves faced with two BIG problems. They had already been forced out of the jungle into the savannas of Africa. Savannas are far more dangerous places to live and survive—more predators, less available food, greater distances to cover. On top of this, they now had to deal with raising these “early-born” infants and children who required their care for longer and longer periods of time. So how do you deal with that without getting wiped out? You bond, you rely upon one another more than ever to help keep the whole troop alive. BUT it’s not quite that simple because at the same time you also have to compete with the very same people you rely on for help. You contend with them for mates, for food, for power and status within the troop. This is one of the great paradoxes of the human condition. We all must both compete and cooperate with one another. This raised the first “moral” questions. Do you put yourself first, or do you put others in the group first? Do you kill, bully or hurt another to get more food, a mate, more power in the short term, and if so, what are the long term consequences? You could be killed or bullied yourself, or tossed from the group, the equivalent of suicide on the savanna. Longer term, you might need that person’s help some day. Maybe thinking a little less selfishly would be a good idea? So we evolved a basic moral code, one in which we want to be treated by others the way we treat them—the golden rule, which is universal and expressed in virtually every human culture on earth.