The evolution of rationality: How chimps process conflicting evidence
arstechnica.com
arstechnica.com
Hmm. By this measure, most Americans today are not capable of rationality.
I'd further suggest that the choice to phrase the idea in terms of a general population with a flaw, and implicitly claiming non-membership in that group, it's possible you're engaging in that same behavior.
... Sometimes, at least in humans, social interactions can also increase our irrationality instead. But chimps don’t seem to have this problem. Engelmann’s team is currently running a study focused on whether the choices chimps make are influenced by the choices of their fellow chimps. “The chimps only followed the other chimp’s decision when the other chimp had better evidence,” Engelmann says. “In this sense, chimps seem to be more rational than humans.”