I would think so. This is an interesting empirical question worth exploring.
I'm sure you're aware of the relationship between higher inter-personal trust and GDP per capita; leaving it for others to explore below! I think this is the closest proxy to fraternity (trust) and higher productivity (GDP per capita):
Productivity differences between developed and less-developed countries are large enough to enable one to be confident that it is not measurement error. Within-country changes in measured productivity over two years or less are not as reliable.
Is some form of fraternity or a larger "Us" a precondition for higher productivity?
I would think so. This is an interesting empirical question worth exploring.
I'm sure you're aware of the relationship between higher inter-personal trust and GDP per capita; leaving it for others to explore below! I think this is the closest proxy to fraternity (trust) and higher productivity (GDP per capita):
https://ourworldindata.org/trust
Productivity differences between developed and less-developed countries are large enough to enable one to be confident that it is not measurement error. Within-country changes in measured productivity over two years or less are not as reliable.
Importance nuance, thanks! I've updated the phrasing to make this salient.