By Shankar Vedantam
Monday, December 31, 2007; A03
Two sociologists and a mathematician recently conducted an experiment that provides an intriguing window into the presidential candidate selection that begins this week. Matthew Salganik, Duncan Watts and Peter Sheridan Dodds had a large group of people rate 48 songs. Based on these ratings, the researchers produced a list of the best songs.
They then had eight other large groups of people evaluate the same songs, with one difference: In each of these “parallel universes,” people knew how others in their group were evaluating the music. Did the eight groups come up with the same list of the best songs? No. When people knew how others thought, this changed how they thought.