That was not the context. It applied to any group of humans.
Therefore, the implication was that European societies were superior to African, for example, because Africans had a regretable tendency to fight tribal wars and enslave one another.
Not sympathetic, thus inferior.
In other words, maybe Bushmen or Blacks were inferior genetically, maybe they were inferior culturally. More likely a combination of both. In any case, they were inferior, in the Darwinian view.
In the context of eugenics, they would be inferior as a society if they were not "sympathetic" regardless of what natural selection did for their physical form. Darwin viewed European Christian society as the most sympathetic, and thus superior to them. Eugenics removes the sympathy of the society that Darwin thought made whites (his European Christian society) strong, making it inferior.
Darwin's argument is also a very good one against abortion. A society that kills its most defenseless cannot be called sympathetic, and thus will fall to other more sympathetic societies.
Well, it does at least raise some interesting issues. Unless one is an idiot multiculturalist, it has to be admitted that some peoples appear to be more admirable than others. Is this genetic or cultural? Or the fault of the leaders of these societies?
I certainly don’t think that all religions, cultures, peoples are equally admirable and never to be judged for their faults.
Yet some of the very worst crimes have been committed by what appear to be the most advanced peoples. Hitler and the Germans were one instance. Mao and the Chinese were another. Then there was Robespierre and the French Terror.