According to Martindale's cognitive theory, the main determinant of aesthetic preference is prototypicality, and preference is usually related to its determinant in a monotonic or U-shaped fashion. Such a relation between aesthetic preference and prototypicality has been proposed before by other investigators. Contrary to their view, it will be argued that prototypicality will not do as a central concept in aesthetics. Aesthetics nearly collapses under the burden of allegedly 'central' concepts. A first approximation to this plethora of concepts yields terms like ambiguity [1], arousal potential [2], canonical form [3], clarity and richness [4], communication [5], effect and means [6], empathy [7], expression [8], illusion [9], information [10], information reduction [11], multiplicity of meaning [12], mystery [13], order and complexity [14], physiognomy [15], prototypicality [16], repleteness [17], symbol [18], synergy [19], tension [20], the analog-digital continuum [21], unity in variety [22], etc. This depressing abundance of 'ideas' is not pruned efficiently because the ideas seldom are put to a solid empirical test. A notable exception is the recent work by Martindale [16,[23][24][25]. His experiments disprove Berlyne's contention that arousal potential is the central concept in aesthetical preference research, whereas, in his view, they support the idea that prototypicality is the main determinant of aesthetic preference, which is related to its determinant in a monotonic or U-sbaped fashion. The aim of this article is to look into the relationship between prototypicality and aesthetic preference in some detail.Membership in a category is not always an all-or-nothing thing. Rather, usually some members are judged to be more typical, better examples of a category than 65