Nearly no one inhabits Greenland and Antarctica, which might help explain why the only visible relative increase in Arctic/Antarctic nationalism comes from enthusiastic polar bears and mildly racist penguins.

I'm not sure there could even exist a particularly satisfying source for this. One of the issues with "soft" sciences is that it can be quite tricky to measure any effects, much less design a viable study that demonstrates causation.

I suppose a social scientist (i.e., not me) could support this claim using ideas from psychology or finding related studies. But I doubt anything will ever be particularly convincing unless we lived in a universe where people told the objective truth and a mandatory survey was asked with the explicit question, "Have the distortions induced by map projections influenced your beliefs regarding people in other countries?"