XIICognitive Bias
Bandwagon Effect
Your bias is Bandwagon Effect. Adopting views because many others hold them.
Why This Bias Happens
Social agreement feels safe. Dissent feels costly. So popularity can masquerade as proof.
Example 1
Marcus reminds himself not to be colored by the crowd. Stoic discipline asks what is true, not what is loud.
Example 2
In markets and politics, cascades form when people copy prior choices instead of private evidence.