Recent years have seen a rapid expansion of efforts to promote social and emotional learning (SEL) in the nation's schools. As some observers have pointed out, though, the growth of the SEL movement poses some challenges. In particular, concerns have been raised about the need for clearer definitions of SEL, less hype, more attention to equity, and a more patient approach to gaining public support. Such constructive criticism is welcome, say two longtime leaders of the SEL movement. But it's important to keep them in perspective and recognize the movement's strengths, as well.