We draw upon data from a prospective, longitudinal study to evaluate the role of typically occurring variations in early experience on development from birth to adulthood. Such an evaluation is complex for both methodological and conceptual reasons. Methodological issues include the need to control for both later experience and potentially confounding third variables, such as IQ or temperament. Conceptual complexity derives from the fact that the effects of early experience can be both direct and indirect, can interact with other factors, and because whether an effect is found depends on what early experience and what outcomes are assessed. Even direct effects are probabilistic and are more in evidence with cumulative than with single measures. Often early experience has its effect indirectly by initiating a chain of events, by altering the organism in some way, and/or by promoting the impact of later experience. We provide examples where early experience is moderated and mediated by other factors and where it shows latent effects following developmental change. We illustrate developmental processes through which early experience has its effect and conclude that despite the complexity of development variations in early experience retain a vital place in the study of development.