30-Second Psychology: The 50 Most Thought-provoking Psychology Theories, Each Explained in Half a Minute - Christian Jarrett 2011
Wason’s confirmation bias
Decision Making & Emotions
Back in the 1960s, the British psychologist Peter Wason presented research participants with four cards, each with a letter on one side and a number on the other. Two of them showed a letter on their upper face, the other two showed a number, rather like this: B, E, 4, 8. The participants’ task was to say which cards they’d need to turn over to test the statement: ’If a card has a “B” on one side, it always has a “4” on the other.’ Most participants said they’d turn over the ’B’ card, which is fair enough—anything other than a ’4’ on the other side would refute the statement. However, the majority of participants then mistakenly said they’d turn over the ’4’. Doing so is pointless. The presence of a ’B’ on the other side would support the statement, but not conclusively. The presence of any other letter would have no bearing on the statement. The other card the participants should have opted to turn over is the ’8’. If this revealed a ’B’, the statement would be falsified. Known as the ’Wason selection task’, this and other research Wason conducted showed our strong ’confirmation bias’ — the tendency to seek out evidence that supports our existing beliefs.
We seek out and pay particular attention to information that supports our existing beliefs.
We read newspapers that espouse our own political views and pay more attention to adverts that champion our favourite brands. What happens when we’re confronted with scientific evidence that directly contradicts our personal beliefs? A 2010 study by Towson University psychologist Geoffrey Munro found that such a situation leads many of us to conclude that the topic at hand, and other topics, too, are not amenable to scientific inquiry — what he called ’the scientific impotence excuse’.
FESTINGER’S BORING TASK
From voting to shopping, to improve your decision making try considering the reasons against, as well as the reasons for, your current favourite.