According to the Gateway Hypothesis, in some cases one substance serves as a gateway for another, more advanced substance. In other words, it is necessary to go through this gateway in order to reach the more advanced substance. In a series of studies (Kandel & Faust, 1975; Yamaguchi & Kandel, 1984a, 1984b; Kandel, 1988; Kandel & Yamaguchi, 1993), Kandel and colleagues have examined the Gateway Hypothesis in detail. In general, these researchers have found that the legal drugs alcohol and tobacco appear to act as gateways for more advanced substances; alcohol plays a somewhat more important role for men and cigarettes play a somewhat more important role for women. Marijuana comes next, followed by cocaine and crack. Collins and colleagues (Graham, Collins, Wugalter, Chung, & Hansen, 1991; Collins, Graham, Long, & Hansen, 1994; Collins, Graham, Rousculp, & Hansen, 1997; Collins, Hyatt, & Graham, 2000; Hyatt & Collins, 2000) have examined the very early part of the onset process, looking at a sample of junior high and high school students. They have found that the onset process usually starts with alcohol; individuals go on either to try tobacco and then have a first experience with drunkenness or to have a first experience with drunkenness followed by trying tobacco. However, a small subset of individuals start their substance use experience with tobacco, go on to try alcohol, and then have a first experience with drunkenness.