These models need not be mutually exclusive; because moderation in these models is a function of the extreme range of perceived peer delinquency (PPD), it is possible that both social control and social expression forces are acting and the moderation function would be cubic in nature. This may also be the case if social distinction and social push were operating jointly. Similarly, both social distinction and social expression forces could be at play in which the association would be quadratic and positive (as opposed to quadratic and negative with the social control/social push model). Although social control here has been applied to substance use, its relevance to dependence is also intrinsic; given use is a pre-requisite for dependence. Very little research of this nature has been conducted in relation to substance dependence.
