In 1978 Japanese roboticist Masahiro Mori was studying the human response to robots and discovered that as robots became more humanlike, people's attitudes toward them became more positive, until the robots got "almost" human, an area he called the "Uncanny Valley." Since they were so close to human, the little bit they were lacking really creeped people out . This effect translated beyond robots to creatures of all kinds and is a good explanation for why we find zombies so scary (that and the fact that they eat brains), why CGI and today's video game characters look so odd. The most interesting application of this theory is for artificial limbs, which suggests that until we can make them indistinguishably perfect, we should stick to more obviously artificial ones. On the upside, designers could go crazy and offer limbs with all sorts of extra functionality, maybe throw a flash drive in one finger and a digital camera in another.