And being able to act like a human being is an essential qualification for a large fraction of the labor market. We might be able to design a robotic nurse capable of performing the medical functions currently performed by nurses, but patients are likely to prefer to interact with human beings in the hospital. Computers are good at math, but children are unlikely to ever respond to a virtual math teacher as well as they will to a flesh-and-blood one. A computer might be better than any human being at enumerating the virtues of a product and answering technical questions, but no computer is going to develop the kind of customer rapport that a good human salesman can.

This isn’t because computers aren’t “smart enough.” It’s because raw intelligence isn’t the only qualification for these jobs. Human beings are social creatures. We care about our interactions with other people in ways that we’ll never care about our interactions with machines, no matter how intelligent they might be. Already, jobs with a social component account for a large fraction of the workforce. As machines become ever better at performing purely mechanical tasks like driving a truck or assembling an iPhone, the fraction of jobs with a significant social component will approach 100 percent.