Physically write a letter to the first offerer, thanking them for the offer but telling them you've found a better position, and hoping that they find another suitable candidate. Sign it.
You don't have to actually send the letter (until you decide to take another position, and even then an email will be better), but it may help you alieve that you are not committed to the first offer.
This greatly reduced the cognitive dissonance. Thanks.
This is the public group rationality diary for January 16-31.
Thanks to cata for starting the Group Rationality Diary posts, and to commenters for participating.
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