Dopamine tightens, not loosens

Depue & Collins propose that extraversion should be separated from the impu lsivity-constraint dimension of personality and that the VTA dopamine syste m is the primary engine of extraversion. Although their focus is on persona lity traits, it may be useful to consider the evidence on psychological sta te changes, related both to affective arousal and to drug effects. This evi dence shows that there are inherent relations between extraversion and impu lsivity-constraint, and that there are influences of dopamine on impulsivit y-constraint that are not consistent with the Depue & Collins model. Increa sed positive affect leads to increased extraversion, and this is associated with more impulsivity and less constraint. The evidence on drug effects sh ows that greater dopaminergic control is associated with more constraint, a nd with anxiety and vigilance rather than positive affect.