Acknowledgments I’m very grateful to Susan Corwith and my colleagues at the Center for Tal-
ent Development at Northwestern University in Evanston, Illinois. Thank
you for sharing your expertise with me. I’m also grateful to all the children
I’ve worked with in the CTD Leapfrog program who have challenged and
amazed me with their curiosity, creativity, and wit. Many thanks to editors
Kyra Ostendorf and Emily Green for their knowledge, encouragement, and
support; I’m grateful for your wise suggestions and editorial guidance.
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