My students, colleagues, and I study cognition and behavior through a combination of psychological and computational approaches. Basic psychological phenomena are simulated, leading to predictions that can be tested empirically. Our recent and current lines of research concern learning and cognitive development, artificial neural networks, evolution, cognitive dissonance, problem solving, and decision making. Common to of all these projects is emergence – the idea that complex phenomena naturally arise from the interaction of elementary components. For example, cognition arises from activation signals passing across networks of neurons. And ethnocentric cooperation emerges from genes replicating themselves.