Is your hair grayer than your parents' at your age?

I ask because I stumbled across pics of my parents, who showed no signs of gray hair at my age, 39. Blessed children of the golden age, they owned their first home together at age 40 with a whopping mortgage of $1100 a month for a 2 bedroom, 1 bath on a .25 acre lot a mile from Venice Beach.

I think it has to do with stress on some level. I saw a few pics of my mom's parents and they had gray hair. Both were living through some pretty tumultuous times... WW2, the great depression, etc.