Development of human-AI ecosystems is perhaps inevitable for a social species such as ourselves. We became social early in our evolution, millions of years ago. We began exchanging information with one another to stay alive, to increase our fitness. We developed writing to share abstract and complex ideas, and most recently we’ve developed computers to enhance our communication abilities. Now we’re developing AI and machine-learning models of ecosystems and sharing the predictions of those models to jointly shape our world through new laws and international agreements. We live in an unprecedented historic moment, in which the availability of vast amounts of human behavioral data and advances in machine learning enable us to tackle complex social problems through algorithmic decision making. The opportunities for such a human-AI ecology to have positive social impact through fairer and more transparent decisions are obvious. But there are also risks of a “tyranny of algorithms,” where unelected data experts are running the world. The choices we make now are perhaps even more momentous than those we faced in the 1950s, when AI and cybernetics were created. The issues look similar, but they’re not. We have moved down the road, and now the scope is larger. It’s not just AI robots versus individuals. It’s AI guiding entire ecologies. How can we make a good human-artificial ecosystem, something that’s not a machine society but a cyberculture in which we can all live as homans—a culture with a human feel to it? We don’t want to think small—for example, to talk only of robots and self- driving cars. We want this to be a global ecology. Think Skynet-size. But how would you make Skynet something that’s about the human fabric? The first thing to ask 1s: What’s the magic that makes the current AI work? Where is it wrong and where 1s it right? The good magic is that it has something called the credit-assignment function. What that lets you do is take “stupid neurons”—little