Postdoc David Sharrow, ’07, ’13, paired up with research professor James Anderson to look at the life span of twins. By digging through the Danish Twin Registry, a database that goes back to 1870, they found that womb-mates live longer than the rest of us. Sharrow and Anderson think it has to do with nurture, not nature: Someone always has your back. The secret to a long life? Grab a buddy and hang on tight.