Run in the family Definition 1 of 1Pro Tip 1/3Common Idiom Understand that 'run in the family' is a common way to say traits are shared by family members. Intelligence seems to run in the family. Pro Tip 2/3Not Always Literal 'Run in the family' can refer to learned behaviors or preferences, not just biological traits. A love for music runs in the family. Pro Tip 3/3No Proof Needed It's often used casually, without needing scientific or genealogical evidence. Being good at chess runs in the family.