Some researchers suggest that there are many types of love. Others suggest one core feature to love that cuts across different types of relationships. For example, in 1977 using factor analysis of 1,500 items related to love, John Lee categorized six major types of love: eros (erotic desire for an idealized other), ludus (playful or gamelike love), storge (slowly developing attachment), mania (obsessive and jealous love), agape (altruistic love), and pragma (practical love). In their own 1984 factor analytic study, Robert Sternberg and Susan Gracek identified one overarching factor, which they termed interpersonal communication, sharing, and support (later called intimacy). In other words, many items on the scale grouped into this single component of love.