Masahiro postulated that initially, as the object of our attention is recognizably not only not human but not really even close to human in appearance, we tend to disregard 'nonhuman' appearance traits, and to anthropomorphize by attributing humanoid motives or reasoning to the object's actions. Pets, for example, look nothing like a person, so any recognizably non-human behaviors they exhibit - or, in the case of Hiro's two variables, non-human movement and non-human appearance - is ignored or interpreted as 'cute' or 'interesting' or other non-person to person cues.

However, at a certain point, as the object grows more human, we tend to stop cataloging the similarities and begin concentrating on the dissimilarities. As a result, highly-humaniform (but not perfect) renderings of people suffer because their motion, for example, looks wrong to people. Similarly, eyes lack some 'glitter', or facial muscles aren't present - these things become central to our perceptions of the object, and as a result, we think of them as 'passing for' human. The corpse, for example, looks almost human - but the color is wrong, there is no animation of the skin or muscles - and people can instantly recognize that there is 'something wrong with this picture.'

Hiro's findings were, of course, intended to aid in producing robots that could be easily accepted by people. His counterintuitive finding was that designers should avoid making their creations too lifelike, for they risked falling into the Uncanny Valley. [...] This may be one reason the 'pseudohuman' characters of Japanese videogames and anime games are more highly regarded than the fetishistically rendered ones of first person shooters.