Some people have argued that they are rarer than other races. At least that is what I've gathered.
It seems that extremely modern and consumeristic cultures have far more incels. Like Japan, Korea, vast majority of the west... I don't know if inceldom is as bad in places like South America. But then again I'm not South American so its not like I have a good idea about it.
Some cultures are far "warmer" in the social sphere than others, and I'd argue that latin cultures are more open, thus there's less inceldom. But that's just me in my ivory tower theorizing.