Humans have engaged in artistic and aesthetic activities since the appearance of our species. Our ancestors have decorated their bodies, tools, and utensils for over 100,000 years. The expression of meaning using color, line, sound, rhythm, or movement, among other means, constitutes a fundamental aspect of our species' biological and cultural heritage. Art and aesthetics, therefore, contribute to our species identity and distinguish it from its living and extinct relatives.

Science is faced with the challenge of explaining the natural foundations of such a unique trait, and the way...