The shape bias: an important piece in a bigger puzzle

No theory remains fixed for ever, at least not until it is abandoned. Theories develop over time. Some changes reflect the discovery of new facts that prompt modification of the earlier version. And often, especially in the case of theories that are tied to mechanisms, changes arise because with time comes a deeper understanding of the mechanism's characteristics. This understanding in turn generates greater precision in the predictions that can be made by the theory. Obviously, a critical issue is whether the changes are post hoc and unprincipled – in which case the theory is at risk of losing credibility – or whether the developments reflect true maturation and greater insight. I believe that changes in the evolution of the Attentional Learning Account (ALA) play a large role in the apparent disagreements that motivate the current set of papers. In fact, there is considerably more agreement than appears on a casual reading of these papers. But I also believe there remain significant points of disagreement. In this commentary, I will try to address what I see as the issues on which there is convergence, and those for which there remain important differences.