Figure 1.

Illustration of the Uncanny Valley Hypothesis. The uncanny valley hypothesis proposes a non-linear relationship between affective experience and physical humanlike realism in appearance and motion (the non-linearity is more pronounced for motion). The key prediction of the hypothesis is that a high degree of human likeness will evoke a sharp negative peak (valley) in affective experience (i.e., along the familiarity dimension). This valley is characterized by feelings of strangeness (and the uncanny). The valley occurs at the point along the dimension of human likeness at which objects are categorically most ambiguous (illustration adapted from MacDorman, 2005).