Abstract
This paper presents 59 new studies (N = 72,310) which focus primarily on the “bat and ball problem.” It documents
our attempts to understand the determinants of the erroneous intuition, our exploration of ways to
stimulate reflection, and our discovery that the erroneous intuition often survives whatever further reflection can
be induced. Our investigation helps inform conceptions of dual process models, as “system 1” processes often
appear to override or corrupt “system 2” processes. Many choose to uphold their intuition, even when directly
confronted with simple arithmetic that contradicts it – especially if the intuition is approximately correct.