Children of the 1980's (like the younger of these two co-authors) may fondly remember a TV cartoon called G. I. Joe, whose closing conceit—a cheesy public service announcement—remains a much-parodied YouTube sensation almost thirty years later. Following each of these moralizing pronouncements came the show's famous epithet: "Now you know. And knowing is half the battle."
While there may be some domains where knowing is half the battle, there are many more where it is not. Recent work in cognitive science has demonstrated that knowing is a shockingly tiny portion of the battle for most real world decisions. You may know that $19.99 is pretty much the same price as $20.00, but the first still feels like a significantly better deal. You may know a prisoner's guilt is independent of whether you are hungry or not, but she'll still seem like a better candidate for parole when you've recently had a snack. You may know that a job applicant of African descent is as likely to be qualified as one of European descent, but the negative aspects of the former's resume will still stand out. And you may know that a tasty piece of fudge shaped like dogshit is will taste delicious, but you'll still be pretty hesitant to eat it.
The lesson of much contemporary research in judgment and decision-making is that knowledge— at least in the form of our consciously accessible representation of a situation—is rarely the central factor controlling our behavior. The real power of online behavioral control comes not from knowledge, but from things like situation selection, habit formation, and emotion regulation. This is a lesson that therapy has taken to heart, but one that "pure science" continues to neglect.
And so the idea that cognitive science needs to retire is what we'll call the G. I. Joe Fallacy: the idea that knowing is half the battle. It needs to be retired not just from our theories of how the mind works, but also from our practices of trying to shape minds to work better.
You might think that this is old news. After all, thinkers for the last 2500 years have been pointing out that much of human action isn't under rational control. Don't we know by now that the G.I Joe Fallacy is just that—a fallacy?
Well, yeah we know, but . . .
The irony is that knowing that the G.I. Joe Fallacy is a fallacy is—as the fallacy would predict—less than half the battle. As is knowing that people tend to experience $19.99 as a significantly lower price than $20.00. Even if you know about this left-digit anchoring effect, the first item will still feel like a significantly better deal. Even if you know about ego depletion effects, the prisoner you encounter after lunch will still seem like a better candidate for parole. Even if you know that implicit bias is likely to affect your assessment of a resume's quality, you will still experience the candidate with the African-American name as being less qualified than the candidate with the European-American name. And even if you know about Paul Rozin's disgust work, you will still hesitate to drink Dom Perignon out of a sterile toilet bowl.
Knowing is not half the battle for most cognitive biases, including the G. I. Joe Fallacy. Simply recognizing that the G. I. Joe Fallacy exists is not sufficient for avoiding its grasp.
So now you know. And that's less than half the battle.