Looking around the article actually posted, I’d place my bets on more control/restraint on violence, for the coordination to be able to form social networks that could overcome any threats of skirmish level, inter-tribal violence:

Paradoxically, low aggression may have been a massive advantage in intertribal warfare. Low aggression could have helped us to form big social groups – tribes of hundreds and thousands. And modern humans don’t just form huge groups, we’re unique among animals in being able to form peace treaties between different groups, and alliances between groups to defend or attack territory. What made modern Homo sapiens so uniquely dangerous might not have been a tendency towards violence and aggression, but friendliness, and the ability to forge alliances. The ability to create groups and social networks, and hold off fighting – at least, until we’re in a position to win – could have given us a decisive edge.

It’s an interesting article, worth reading in its entirety.

Selection for juvenile traits – low aggression, openness to novelty and new people – likely made us more social, and produced our immature-looking skulls as a side-effect. Ironically, it may have been this sociability and low aggression that made modern humans so incredibly dangerous to these primitive Homo sapiens.

So we partied the others to death?

Our name is Homo Buckiens and we’re here to fuckiens.

This article does a lot of speculation from few facts but is truly compelling.

I appreciate the clarity the article uses in the factual support for the ultimate theory, building on each inferential step that seems pretty obviously correct. The stuff that’s actually presented as being fairly certain:

• The fossil record shows many lines of archaic homo sapiens whose physical features don’t share modern homo sapiens’ “juvenile” baby face characteristics.
• The dating of those fossils and the migration patterns of our known ancestors suggests that these archaic homo sapiens aren’t actually our ancestors, but were outcompeted by our branch.
• The anthropological record shows that these archaic homo sapiens weren’t as dominant as our ancestor branch, but were close and could hold their own. Apparently the ancestors of modern humans never lost territory, even if it took millennia to displace other hominids.
• These archaic branches had some limited tool use, and some evidence of trade and ceremonial burial.

The article presents theories about our branch being less violent, having less aggression, able to build lasting alliances with larger groups of tribes. But it’s grounded in some interesting facts that are interesting, in themselves.