When you think of a family business, one of two images probably comes to mind: either the mom and pop shop around the corner or the dysfunctional family from “Succession.” But actually, “it could be anything,” says Jennifer M. Pendergast, family enterprise consultant and professor at Northwestern University’s Kellogg School of Management. Last episode, we looked into the oldest family business in Chicago. And this got us thinking about family enterprise in general: Why do family members end up in business together? What happens when they do? Should they? Curious City’s Erin Allen sat down with Pendergast to talk about this, plus why she says family business is the “backbone of the economy.”