Do you have an expensive but uncomfortable pair of shoes or jeans at the back of your cupboard that you never ever wear, but you simply cannot throw away because to do so would be to admit defeat and recognise that you wasted a lot of money? If so, you are suffering from the sunk-cost bias or fallacy, writes Dr Christian Jarrett for the BPS Research Digest.
Help is at hand in the form of a new study by researchers at INSEAD in Singapore and The Wharton School at the The University of Pennsylvania. Andrew Hafenbrack and his colleagues claim that just fifteen minutes practice at mindfulness meditation reduces people’s vulnerability to the sunk-cost bias – our usual tendency to persist with lost causes because of what we’ve already invested.
Mindfulness meditation is all about learning to stay in the moment, and the researchers think it probably helps reduce the sunk-cost bias because the error is partly caused by memories of prior investments, and also by anticipation of regret in the future if a project or prior purchase is abandoned.
The researchers first surveyed 178 adults online and found that across the sample, a natural tendency to stay in the moment (called “mindful attention awareness”) tended to correlate with being less prone to the sunk-cost bias.
In two further experiments, involving hundreds of undergrads, Hafenbrack and his colleagues found that just fifteen minutes of guided, breathing-based mindfulness meditation led to less vulnerability to the sunk-cost bias, as measured by one of two hypothetical business decisions.
Resistance to the sunk-cost bias in the first scenario required choosing to buy a superior printing press even though money had already been invested in older technology; resistance in the second scenario required making the decision to discontinue investment in a stealth plane because a rival model made it obsolete. In both cases, participants who undertook the mindfulness training demonstrated less sunk-cost bias (78 and 53 per cent resisted it, respectively, across the two studies), as compared to participants in the control conditions who were instructed to spend the same amount of time mind wandering and thinking of whatever came to mind (just 44 per cent and 29 per cent, respectively, resisted sunk-cost bias).
One further study with 156 online participants looked for mediating factors. This showed that the benefit of mindfulness meditation was mediated by less focus on the past and future, and less negative affect.
“It is particularly notable in this set of studies that increased resistance to the sunk-cost bias occurred after only a brief recorded mindfulness-meditation induction,” the researchers said. Critics might wonder about the lack of a true baseline control condition. Can we know for sure that the mind wandering control condition didn’t elevate sunk-cost bias? Also, we need to know more about the longevity of the mindfulness effect on sunk-cost bias – in this research the test always came right after the meditation.