come from good stock

To be born into a respected or respectable family. A reference to selective animal breeding, in which "good stock" refers to a desirable breed or pedigree. A: "Do you know Susie Perkins?" B: "Not directly, but I've had dealings with her family for decades. She comes from good stock." Loyal, honest, hardworking—you can tell he comes from good stock. I'm surprised Johnny is such a troublemaker because I know he comes from good stock.