The claim that the being who ends up exerting significant effort and time to reproduction (effort that immediately and directly eats into the non-reproductive economic output) is looking for a mate with enough spare (earning/capital) capacity to support themselves and a family is extraordinary?
The claim that I think is "extraordinary" is that a focus on specifically income is found in "every culture on the planet."
Is this really true of the Sentinelese, an indigenous culture in the Indian ocean? Maybe if we define "income" in some funny way. There's a long history of "big man" cultures in anthropology, wherein authority and persuasion are more important that direct "income."
But, then, "income" is so tied to the modern capitalist framework that it's hard to even talk about this sort of thing, which is really my main point.
It's simply unreasonable to assume that the Sentinelese men who are best at procuring food/resources/etc aren't more desirable than their peers. Social status is likely a factor as well.
Authority is often derived in tribal cultures from being the best hunter/warrior, or being the son of the best fighter if the tribe has a monarchal structure of leadership transfer.
Not that any of us know, because the Sentanalese will kill us on site as trespassers if we show up on their islands.
Right, I think your hypothesis is reasonable. I think your degree of confidence in it, though, is not. I don't think you have evidence for it that stretches as far as "every culture on the planet."
Could you provide a cite for this? It's an extraordinary claim. It doesn't match with my understanding of some historical cultures.