ABSTRACT
“Birds of a feather flock together.” Such truisms are not always true, but in the case of substance use the old saying is largely valid. Earlier research, summarized in chapter 2, showed consistently that drug-using youth and young adults are likely to have friends who use the same substances. We thus expected that respondents who engaged in various substance use behaviors, and especially those who did so fairly often, would report that relatively high proportions of their friends also engaged in such behaviors. That is exactly what we found, as is detailed in this chapter.
