>>281149038Probably some degree of conflation but I stand by the idea that you naturally desire some degree of inbreeding in the population for optimal fitness. some lab studies and human birth records imply that range is somewhere around 1% relatedness.
Genetics is a tricky topic. you want some level of mutation to generate new traits but you need to purge out the bad genes.
I've definitely seen studies that compared levels of fitness drop in populations with varied histories of inbreeding or outbreeding that showed variation in the degree of inbreeding depression but also outbreeding depression.
I feel like the biggest risk with inbreeding is the loss of heterozygote advantage traits and recombination. yet clearly outbreeding and too big a population have their own issues.