In line with these ideas, Cloninger and his colleagues developed the Temperament and Character Inventory (Cloninger et al 1994), a seven-factor scale measuring four temperament and three character dimensions. Cloninger and his colleagues claimed that the temperament dimensions of novelty seeking, harm avoidance, reward dependence, and persistence are genetically homogeneous and that two of them are associated with distinct neurochemical substrates: novelty seeking with dopamine, and harm avoidance with serotonin. The model also identified three character dimensions called self-directedness, cooperativeness, and self-transcendence, which are based on social goals and values. According to Cloninger and colleagues (1996), the psychobiological model accounts for the genetic basis of the personality phenotype, whereas alternative models of personality comprise genetically and environmentally heterogeneous factors.
