There’s been a lot of talk recently about the ways in which cognitive biases (such as confirmation bias, framing effects, and the bandwagon effect) lead to errors in reasoning, and the related question of whether (paternalistic) steps should be taken to mitigate their effects. (I’m looking at you, Cass Sunstein.)

Much of this discussion proceeds as though these biases are fairly recent discoveries, with most participants in the debate citing the work of Daniel Kahneman and Amos Tversky as the font of our knowledge of them. But given the attention that’s traditionally been devoted in philosophy to critical thinking, I’d be shocked if many of these biases hadn’t been identified (and ways to mitigate them discussed) long ago.

So, I have a question: What are the earliest examples of these biases that you’ve encountered?