What is the meaning of runs in the family idiomatic expression?

The idiomatic expression "runs in the family" refers to traits, characteristics, or conditions that are common among family members, often passed down through generations. This can include physical features, health issues, or personality traits. For example, if a specific health condition is prevalent among relatives, one might say it "runs in the family." Essentially, it highlights the hereditary nature of certain attributes within a familial lineage.