The ability to understand complex causal relations in the world is becoming ever more important for students, workers, and leaders. For many years, Tina Grotzer, one of the nation’s leading researchers on the development of scientific thinking, has focused her work on this cognitive capacity; she has done more than anyone to elucidate how such complex forms of thinking can be acquired. Her book on this topic will be of great interest to researchers, educators, parents, and others who want to see our children use their minds well.