Repeat: Truth decay

(This episode first aired in February 2020, and has been updated to reflect all that's happened in the world since.) How do we know what we know? In a digital landscape where social media dominates, and most people don't trust mainstream reporting, how can we be sure what we're seeing is actually real?

It's a question technology journalist and Atlantic magazine staff writer Alexis Madrigal has contemplated a lot, and he's finding a lot of noise among the signals of truth.

So what does this mean, more broadly? Social psychologist Arie Kruglanski says that humans need a shared concept of "truth" in order to have societal cohesion. And when that shared concept dissolves, bad things happen. Arie explains the collective risks of our unshared realities.