The real challenge for developmental psychology is to understand the how of development, and not just the what of development. Such causal theories need to explain behaviours at multiple timescales. They must explain how and why behaviours unfold online, as observed in real time, as well as how they unfold in developmental time — across the lifespan of the individual. Volume 1 of this book briefly tackled the importance of models in several places, and even sketched a few key models that illustrated the processes. In this book, Volume 2, nine different research labs with objectives broadly consistent with the neuroconstructivist approach present their computational modelling work.