Psychology is very often how societies avoid looking in the mirror. A major structural reason for the surging interest in happiness is somewhat more disturbing, and concerns technology. Until relatively recently, most scientific attempts to manipulate how someone else was feeling occurred within formally identifiable institutions, such as psychology laboratories, hospitals, workplaces, focus groups, or some such. This is no longer the case. In July 2014, Facebook published an academic paper containing details of how it had successfully altered hundreds of thousands of its users’ moods, by manipulating their news feeds. There was an outcry that this had been done in a clandestine fashion. But as the dust settled, the anger turned to anxiety: would Facebook bother to publish such a paper in future, or just get on with the experiment anyway and keep the results to themselves?