Click here to watch the TEDTalk that inspired this post.
It's true that babies know more than psychologists believed a century ago. However, I doubt kids know as much as Alison Gopnik claims they do. For that matter, most adults are no great shakes in the logic department.
Kids are pretty good at solving the kinds of simple problems Gopnik presents in her experiments. However, these are the same kids who have no problem believing Santa manages to fly around to billions of homes on one Christmas eve, or that trees can talk, or that stuffed animals have human personalities.
Adults, for their part, have a long history of rather lamentable logical mistakes. We're especially prone to confusing correlation and causation. That's what has led us, at various times in various places, to engage in animal and human sacrifices, burn witches, and blame vulnerable minorities for causing the crops to fail or diseases to spread. It's only in the past 500 years, with the rise and spread of scientific thinking, that we've learned to avoid some of these mistakes, but even now, most of us engage in magical thinking of one kind or another. That's what keeps people believing in "lucky" numbers and colors, and in angels and demons, as well as going to casinos and buying lottery tickets.
Dr. Gopnik also exaggerates the "evolutionary" division between childhood and adulthood, with childhood as a time of preparation and learning and adulthood a time for work. In most human cultures until quite recently, and even today in many, kids begin contributing work to their families from early childhood onward -- fetching water, collecting firewood, helping with meal preparation, taking care of younger children. That we rely little on kids' work today in developed countries is not "evolutionary," but due to economic and technological changes that make us less in need of their labor and make them more in need of school-based learning in order to prepare for adult jobs. As I've proposed in my articles and books, we've even added a life stage of "emerging adulthood" in between adolescence and young adulthood, to allow people like Dr. Gopnik's 23-year-old son to take their time not just to find work but to find something they really want to do. That's a luxury we can afford in developed countries, because we don't need their labor in order to survive. But it doesn't have anything to do with evolution.
In general, we should be very careful about attributing the features of human development in the world immediately around us to "evolutionary" influences. The way we live now in developed countries is different than humans have ever lived before. We have fewer children, our children are more likely to survive to adulthood, we're kinder to them, we eat better, we have fewer diseases, it takes us longer to prepare for adult work, we're less likely to die in childbirth, we're more likely to seek intimacy in marriage and fulfillment in work, we live longer... it's a long list. If something in human behavior is truly evolutionary, it should be evident in many cultures and through eons of history. I doubt Dr. Gopnik's assessments of children's "scientific" thinking qualifies, but I think magical thinking does, throughout the lifespan.
Given our species propensity for irrational and magical thinking, it's remarkable that we've been able to develop technologies and a body of scientific knowledge that require us to overcome those tendencies. But the tendencies are still there, in all of us, young and old alike.