"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." How old are you, exactly? That used to be an easy—if impertinent—­question to answer. It turns out the ...

Add Yahoo as a preferred source to see more of our stories on Google. Biological age tests are becoming popular with biohackers and longevity seekers. They're not perfect health indicators, but they ...

Every item on this page was chosen by a Town & Country editor. We may earn commission on some of the items you choose to buy. How old are you, exactly? That used to be an easy—if impertinent—­question ...

How old are you, exactly? That used to be an easy—if impertinent—­question to answer. It turns out the truth is a moving target. There’s your chronological age—the number of candles on your birthday ...