Slavery split men and women in certain ways
Many studies have been done to illustrate that there is a split in black communities between men and women to greater extents than in other communities, and the thesis of this book is that this split actually occurred as a direct consequence of slavery, since slave owners treated men and women so differently that communities developing over shared experience led to a split community with a difference between the genders.
Slaves were treated as sub-human
The treatment of slaves is absolutely inhumane, literally, because the treatment depends on the radically hateful opinion that black people aren't really people, that they are animals. Therefore they have different functions as a type of live-stock, and the women matter differently because they make more property for the owner through child birth. This is incredibly hateful and bigoted treatment that constitutes sociopathy and psychopathy.