“…In fact, literature II relevant to biologically-mediated individual differences in nicotine's effects indicates that nicotine is the agent responsible for the major reported effects of smoking. Specifically, in empirical studies, nicotine administration decreased body weight in humans and rats (Grunberg, 1982;Winders & Grunberg, 1989), decreased aggression in humans (Cherek, 1981;Cherek et aI., 1991) and in rats (Silvennan, 1971;ScheufeJe, 1997), and altered biochemical and behavioral responses to stress in rats (Benwell & Balfour, 1982;Cam & Bassett, 1983;1984;Sharp, Beyer, Levine, Morley, & McAllen. 1987;Peck, Dilsaver, & McGee, 1991;Acri, 1992Acri, , 1994Takada, Thara, Vrano, & Takada, 1995) and in humans (MacDougall, Musante, Castillo, & Acevedo, 1988;Gilbert, Robinson, Chamberlin, & Spielberger, 1989;Pomerleau & Pomerleau, 1990;Levin, Rose, Behm, & Caskey, 1991;Smits, Temme, & Thien, 1993).…”