Much of developmental science aims to explain how or whether children's experiences influence their thoughts and actions. Developmental theories make assumptions and claims—what I call ecological commitments—about events outside research contexts. In this article, I argue that most developmental theories make ecological commitments about children's thoughts, actions, and experiences outside research contexts, and that these commitments sometimes go unstated and untested. I also argue that naturalistic methods can provide evidence for or against ecological commitments, and that naturalistic and experimental studies address unique yet complementary questions. Rather than argue for increasing the ecological validity of experiments or abandoning laboratory research, I propose reconsidering the relations among developmental theories, naturalistic methods, and laboratory experiments.