Can Social Networking Change the Human Brain

Consider, for example, the fact that the size of military units has not changed materially in thousands of years, even though our communication technology (from signal fires to telegraphy to radio to radar) has. The basic unit in the Roman army (the “maniple”) was composed of 120-130 men, and the size of the analogous unit in modern armies (the company) is still about the same. The fact that effective human group size has not changed very substantially — even though communication techno...