Brinley plots and theories of aging: the explicit, muddled, and implicit debates.

We evaluated the debates concerning Brinley plots and the associated theories of age-related slowing. We concluded that an explicit debate regarding a single-factor, general slowing model was no longer a debate as most, if not all, agree to the disconfirmation of that model. We address sources of confusion in the debates that have muddled the areas of genuine disagreement. When the confusion is lifted, the remaining debate centers, rightly, on evaluation of theories of aging. We show that Brinley plot analyses can lead to both falsely accepting and falsely rejecting theories of age-related slowing. Although plotting data most certainly can assist with the evaluation of cognitive theory, we argue that models of performance and learning must play a more central role in advancing theories of cognitive aging.