For colleges eager to attract the best students, the quality of student housing is a key selling point. That shouldn't mean putting a Jacuzzi in every dorm, warns Susan Painter, a design psychologist. Painter, who holds a Ph.D. in behavioral psychology, uses her knowledge of human behavior to advise colleges on building design. Give students too many amenities, she says, and they'll hole up in their rooms instead of participating in campus life. A senior planner at AC Martin Partners, a Los Angeles architecture firm, and a principal at her own design-psychology practice, Painter talked with The Chronicle Review about how colleges can make smart design decisions.