Nonsense. It's a matter of culture and parenting. That, and the residual rage, for which the slave-owning culture, and governments which perpetuated it, are directly responsible.
There's nothing inherent in anybody's genes that makes people savage.
The vast majority of blacks live peaceful, non criminal lives, and aren't racist, just like the vast majority of whites.
In general, this is true for all American ethnicities. As usual, a few bad apples give a bad name to the whole group.
ping to later
We will agree to disagree.
Bears repeating.
Until the inner city culture changes, this will continue to be a problem. A few more Bernie Goetz situations will get some attention, especially if people get out of dodge and don't call the cops or "just us" department afterward.