You can thrive as you age. Positivity may be key.

New research from Yale shows that people are just as likely to improve as they age as decline — and a positive outlook can make a difference. At 84, marathoner Carol Wright says running is more than just exercise. It connects her to others and gives her goals. Two doctors say even if you aren't as fit as Carol, you can thrive too, but we also need a societal rethink of aging.