For the first few days of his artificial life, after the box from Sony arrived and the batteries were charged, my AIBO robot dog behaved pretty much the way I’d expect a mechanical puppy to behave—he lurched around the house, emitting digital-sounding bleeps of pleasure every time my 2-year-old son petted him on the head. He learned to shake and would reliably sit on command. He ran into the occasional wall, of course, but he never made a mess on the carpet.