We imitate others constantly, and mostly without noticing it

Berger opens with the classic finding that people will conform to an obviously wrong group answer simply because everyone else gave that same wrong answer, famously demonstrated when a majority of participants matched an incorrect line length rather than trust their own accurate judgment. He identifies three drivers: using others as a shortcut when we're uncertain, feeling social pressure to avoid standing out, and automatic, below-conscious mimicry with no deliberate decision at all.

That automatic layer connects to the discovery of mirror neurons, brain cells that fire both when performing an action and when watching someone else perform it, suggesting a neurological basis for why humans mimic each other's gestures. Berger cites a negotiation study where people who subtly mirrored a counterpart's body language were substantially more likely to close the deal, since mimicry generated rapport neither party consciously registered.

The broader point is that imitation isn't a character flaw; it's built into how humans process uncertainty and build connection.

Takeaway: before trusting a strong shared consensus, check whether it reflects real independent judgment or just cascading imitation.