This book contains edited chapters on current work concerning connectionist or neural network models of human development. A starting point of the approach is that the brain comprises millions of nerve cells (neurons) that share a myriad of connections. Human development in these systems is typically characterized as adaptive changes to the stregnths of these connections. Many examples are provided of how researchers have built computer programs that mimic these processes so as to provide a better understanding of human intellectual development. Alongside this work in artificial intelligence, other chapters describe what is currently known about how real brains develop.