be in (one's) DNA(redirected from were in their D.N.A.)
be in (one's) DNA
To be a core aspect of one's character, motivation, or lineage; to be an intrinsic or fundamental part of one. He's always been that way, ever since he was a small boy. Helping others just seems to be in his DNA. This company has been drilling oil since my great-grandfather first struck crude oil back in 1902. It's in our DNA!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.