Professor Geoff Greif is quoted in a GetOld.com story that looks into how siblings can improve our health. "Our bonds with our brothers and sisters are inescapable. “That’s what makes them so important,” says Geoffrey Greif, PhD, co-author of the book Adult Sibling Relationships. “If I have friends I don’t like, I can drop them. You can divorce a husband or wife. Siblings are inescapable.”