It is hard to imagine that anyone thinks of goodness as a problem, but Charles Darwin did. The little worker bees that sacrificed themselves to protect their hives – the ultimate example of animal goodness – kept Darwin up at night.
Given Darwin’s ideas about evolution natural selection were correct (and, of course, they were and are), then this sort of altruism should be extraordinarily rare in nature. If increased reproduction is the ultimate end all and be all of evolution by natural selection, then altruists should disappear – and fast. But they don’t disappear, and Darwin was so puzzled by this that he spoke of altruism as a problem that could prove fatal to his whole theory of evolution.
Then a solution to this nasty conundrum hit Darwin like a ton of bricks. Worker bees weren’t helping just any old bunch of bees; they were protecting their hive. And their hive contained special individuals: blood relatives.
Blood relatives are, by definition, very similar to one another. So even though the little worker bees may have been giving up their lives, by doing so they were potentially saving hundreds of blood relatives. In modern parlance, we’d say that the worker bees were helping blood kin, because blood kin are genetically related. By helping your blood relatives, you are indirectly promoting the reproduction of copies of your own genes - copies that just happen to reside inside your kin.