Investigation of Cloninger's subtypes in a male alcoholic sample: applications and implications. 
Cloninger's Type 1/Type 2 classification scheme was examined in 82 male alcoholics.  Only 16% were classified by presence/absence of Type 1/Type 2 symptoms.  When age of symptom onset was considered, 75.6% were classified into early (ESO) and late symptom onset (LSO) groups.  Relatively few group differences were found: ESOs were younger, had lower SES, began drinking earlier, reported greater frequency of maternal alcoholism and more severe paternal alcoholism, and reported more antisocial behaviors.  ESO/LSOs did not differ on neuropsychological performance, although both performed poorer then controls.  Differences between these findings and those found with female ESO/LSO alcoholics are discussed and clinical implications considered.