Hmmm. Wonder to what degree other primates are inbred.
Excellent question. The great apes also live in small populations. One difference between them and us, though, is the increased sexual activity of our species and likely the pre-human species too.
Humans have an effective population size of 1000 to 2000 people, meaning that we could replicate the entire human genetic diversity in 1K to 2K people.
A group of any 55 chimps has more genetic diversity than the human race. This is probably due to humans having fewer chromosomes than other apes (at some point, this mutation slashed our species’ population), and compounded by the Mount Toba eruption 70K years ago that cut our numbers to maybe 10K people.
We’ve been through more population bottlenecks and thus have far less diversity than other primates. Though they’ll catch up because their populations have fallen significantly.