Markus H. Schafer and co-author Tetyana P. Shippee, a Purdue graduate who is a research associate at Purdue's Center on Aging and the Life Course, compared people's chronological age and their subjective age to determine which one has a greater influence on cognitive abilities during older adulthood. Nearly 500 people ages 55 to 74 were surveyed about aging in 1995 and 2005 as part of the National Survey of Midlife Development in the U.S. What they found was that these people who felt "young" for their age were more likely to have greater confidence about their abilities a decade later. It seems that, while the chronological age was important, the subjective age had a stronger effect. I believe that how old you are matters, but beyond that it's your own personal interpretation of your "age" that has far-reaching implications for the process of how and when you "actually" begin aging. For example; if you feel old beyond your own chronologic...