Fast-Track Toddlers

Considering that there's essentially no science to support it, the Mozart effect has had a pretty good run. Parents all over the U.S. have been playing the Austrian composer's music to their infants and toddlers on the theory that it stimulates brain development. Even a few state governments have got into the act: Georgia and Tennessee are giving classical-music CDs to new mothers, and Florida has mandated that state-run day-care facilities play such music each day.

In fact, though, the original research behind this attractive notion said nothing about infants or even about intelligence, and it certainly made no claims about...