Yes, it was widely reported in debates in ancient Athens and the Roman empire.
But I wrote "Social media did a lot to foster outrage and destroy nuanced thinking.", which is different.
Humanity has never seen before a billion-dollar industry generating user engagement by fueling online altercation.
Instant gratification, dopamine cycle addiction and all of that.
Human experiments being activities defined by the subject instead of the object make more sense. Can you have the human-involved experiment with just the objects occur naturally?
You cannot just leave the props lying around a college campus and get a Milgram's experiment replication attempt. You cannot just have a freezing chamber or scalpels to repeat the horrors of nazi Germany and Unit 731.
Way before social media, there was short wave radio, then cable news which introduced the 24-hour news cycle, and entertainment-shows-disguised-as-news with their permanently outraged talking heads (think Rachel Maddow or Tucker Carlson).
Political polarization is older than social media, and it wasn't emergent - it was a deliberate political tactic and it worked well enough until the other side adopted it too. It's like an iterated prisoner's dilemma and both sides are now locked into a cycle of defecting - doing otherwise makes no sense, and there aren't many deescalation off-ramps.