In Brief

Capuchin and squirrel monkeys prefer symmetrical pictures and those with elements repeated at common intervals more than random patterns, according to new study published in the Journal of Experimental Psychology: Animal Behavior Processes (Vol. 31, No. 1). The findings suggest that human aesthetic preferences may have ancient evolutionary and genetic roots, says study author James Anderson, PhD, a reader in the psychology department at the University of Stirling in Scotland.

To reach this finding, Anderson and his colleagues presented six capuchin monkeys and seven squirrel monkeys with two cards at a time. One card in the set pictured a repeating pattern or a symmetrical design, and the other pictured the same figure scrambled into asymmetry.

Monkeys of both species picked up the symmetrical or regularly patterned cards more often than the scrambled ones. And some scorned scrambled cards almost 100 percent of the time.

The findings, along with other studies that show infants prefer gazing at symmetrical pictures, suggest a genetic basis for aesthetic preferences, Anderson says. And, since the ancestors of capuchin and squirrel monkeys split off from human-related primates about 36 million years ago, the attraction to symmetry and regularity may be older than scientists previously thought, he notes.

"The behavior of some of the monkeys as they manipulated the cards suggested a real fascination with the patterns," says Anderson.