What are the effects of deliberation about political issues by likeminded people? An experimental investigation involving two deliberative exercises, one among self-identified liberals and another among self-identified conservatives, showed that participants' views became more extreme after deliberation. Deliberation also increased consensus and significantly reduced diversity of opinion within the two groups. Even anonymous statements of personal opinion became more extreme and homogeneous after deliberation.

What are the effects of deliberation about political issues by likeminded people? An experimental investigation involving two deliberative exercises, one among self-identified liberals and another among self-identified conservatives, showed that participants' views became more extreme after deliberation. Deliberation also increased consensus and significantly reduced diversity of opinion within the two groups. Even anonymous statements of personal opinion became more extreme and homogeneous after deliberation.

Krueger & Funder (K&F) spend too much time on their critique of some classic studies in social psychology. They should have spent more time developing their constructive ideas about better methodologies and, especially, better conceptual foundations for the field. We endorse their exhortation to consider social behavior in its ecologically adaptive context, and we present a few ideas of our own about how to develop a more comprehensive conceptual framework.