InastudyjustpublishedinthejournalIntelligenceusingsearchtermssuchas“stupidthingtodo”BalazsAczelandhiscolleaguescompiledacollectionofstoriesdescribingstupidmistakesfromsourcessuchasTheHuffingtonPostandTMZ.Theresearchersthenhadasampleofuniversitystudentsrateeachstoryontheresponsibilityofthepeopleinvolvedtheinfluenceofthesituationtheseriousnessoftheconsequencesandotherfactors.

Analysesofthesubjects’ratingsrevealedthreevarietiesofstupidmistakes.Thefirstiswhenaperson’sconfidencegoesbeyondtheirskillaswhenaPittsburghmanrobbedtwobanksinbroaddaylightwithoutwearingadisguisebelievingthatlemonjuicehehadrubbedonhisfacewouldmakehiminvisibletosecuritycameras.

Theconfidence-skilldisconnectionhasbeennamedtheDunning-KrugereffectafterastudybysocialpsychologistsDavidDunningandJustinKruger.DunningandKrugerhadCornellundergraduatesperformtestsofhumorlogicandgrammarandthenratehowwelltheythinktheyperformedcomparedtoothersubjectsinthestudy.Theworstperformingsubjectswhosescoresputtheminthe12thpercentileestimatedthattheyhadperformedinthe62ndpercentile.SummarizingthefindingsDunningnoted“Poorperformers—andweareallpoorperformersatsomethings—failtoseetheflawsintheirthinkingortheanswerstheylack.”Whenwethinkweareatourbestissometimeswhenweareatourobjectiveworst.

Asanynumberofpoliticalscandalsillustratethesecondtypeofstupidmistakeinvolvesimpulsiveacts—whenweseemunabletokeepourbehaviorincheck.InthescandalthatbecameknownasWeinergateformerU.S.representativeAnthonyWeinersentbluetextsandpicturesofhimselftowomenhemetonFacebook.(AfterresigningWeinercontinuedhiscyber-dalliancesandthenfellpreytotheDunning-Krugereffectwhenheoverestimatedhissupportinthe2013NewYorkCitymayoralprimary;hereceived5%ofthevote.)

Thefinalvarietyofstupidmistakeinvolvesfailingtoconcentrate—HomerSimpsonesqueD’ohmoments.AsarguablythebestexamplefromAmericansportshistoryinthe1929RoseBowlUniversityofCaliforniastarRoyRiegelsrecoveredafumble(失误球)andreturnedit65yardsthewrongway.Riegel’smistakesetupasafetyf