sentences:  Hare and colleagues have criticized the Cooke & Michie three-factor model for statistical and conceptual problems, like in fact consisting of up to ten different factors and resulting in impossible parameters (negative variances).In the 2003 edition of the "PCL-R", Hare added a fourth antisocial behavior factor, consisting of those factor 2 items excluded in the previous model.Again, these models are presumed to be hierarchical with a single, unified psychopathy disorder underlying the distinct but correlated factors.