Stimulus energy does not account for 2-month-olds' face preferences.

We examined the determinants of 2-month-olds' preferences among facelike and abstract patterns. Observed preferences were compared with the predictions of two preference models--one based on stimulus energy (as measured by the amplitude spectrum) and the other based on stimulus structure (as measured by the phase spectrum). It is known that the phase spectrum is the primary determinant of perceived identity to adults. Twenty-five 2-month-olds saw six pairings of four patterns: a schematic face, a lattice, a pattern composed of the amplitude spectrum of the lattice and the phase spectrum of the face, and a pattern composed of the amplitude spectrum of the face and the phase spectrum of the lattice. Only patterns with the face's phase spectrum look facelike to adults. Unlike the preferences of newborns (Kleiner, 1987), 2-month-olds' preferences could be predicted from the phase spectrum but not from the amplitude spectrum. In other words, the 2-month-olds preferred the patterns that looked facelike to adults. These results offer clear evidence that 2-month-olds' preferences for facelike patterns are not governed by stimulus energy.