'Smart People'' is the darkly comic story of Lawrence Wetherhold, a widowed and unhappy English professor (Dennis Quaid), who has alienated his son and turned his daughter into an overachieving, friendless teen. He falls for Janet (Sarah Jessica Parker), one of his former students, while at the same time his ne'er-do-well brother (Thomas Haden Church) shows up at his door unexpectedly, triggering a series of comic crises and eventually growth in the family as they learn to reconnect.