I notice that some anthropologist believe all humans were egalitarian in the past, and others believe inequality was more common they we currently we think with hunter gathers.
This seems to along with anthropologist using modern hunter gathers as way to look at the past which is now considered not a best practice from what I read. Which this influenced the egalitarian hunter gathers idea even more.
In all honesty I think if you want a tabula rasa approach then how toddlers and kindergartners organize and interact is somewhat of a possible indicator, with empathy being a huge development milestone in children and that many are naturally sharing when an individual is in visible duress. I think one approach in anthropology and recent historical research that should be supported more is to view current hierarchical society as maladaptive states of humanity under stress either via system/environment or stress via others as previous viewpoints on society and organizing viewed these things as stepping stones of advancement instead.