Comparison
Projection Bias vs False Consensus Effect
Main difference in one sentence
Projection Bias assumes another person thinks or feels like you do, while False Consensus Effect assumes lots of people probably agree with you.
Brain Shortcuts that Tilt Judgment
Cognitive Biases
Projection Bias uses your own current motives, preferences, or emotional state as a shortcut for another person's inner world.
Brain Shortcuts that Tilt Judgment
Cognitive Biases
False Consensus Effect uses your own viewpoint and your immediate circle as a shortcut for how common that viewpoint must be in the broader population.
Example where people confuse them
A manager loves speed and assumes one specific teammate also wants a fast decision. That is Projection Bias because one person's mind is being modeled after the manager's. If the manager then says most employees probably want the same thing, that becomes False Consensus Effect because the claim expands from one mind to the whole crowd.
Quick memory trick
Projection Bias says, "You are probably like me." False Consensus Effect says, "Most people are probably like me."