individuals and thus into their higher perceived Darwinian fitness—in deviant social groups (Vanyukov et al., 2003b). Inasmuch as antisociality is associated with substance abuse, the latter also turns into an indicator of fitness benefit. The existence of such groups is consequently perpetuated as long as they serve a means to convert what is considered a disadvantage in the contemporary mainstream society (and/or discouraged there) into a benefit. This allows the individual to take comfort in group protection, cooperation and reciprocal altruism, thereby increasing their perceived fitness (Vanyukov, 2004). While homophily may be one of the mechanisms facilitating prosocial behavior toward non-relatives, drug use may be one of the readily observable phenotypic indicators of the latent traits that such groups assort on, facilitating such assortment.
