Beware: This common decision-making advice probably doesn’t help

If you’ve ever publicly fretted over a huge decision, you’ve definitely been told: “Just sleep on it.” After all, whether you’re thinking of quitting your job, moving across the world, or getting a substantial haircut (we get it), most of us give a lot of time and thought to these choices. Since getting enough sleep is generally correlated with higher energy levels, aka more brain “awakeness” (not the scientific term), it stands to reason that getting a good night’s rest before making a potentially life-altering decision is a good call. (And for the more psychic-inclined of us, it gives a chance for your subconscious to chime in.)

However, a new study conducted by at the Harvard Business School suggests that getting a good night’s sleep doesn’t totally help clarify the decision-making process. What’s more? It might actually make it more confusing. Published in the Journal of Behavioral Decision Making, which has an amazingly specific name, the study showcased the results of two experiments involving, of all things, laptop satchel bags. The bags were displayed alongside positive and negative reviews; study participants were then asked which satchel they liked the best, and also told that they were going to be entered into a raffle for said satchel.

For one study group, they received that information in the morning and then re-quizzed on their “favorite” satchel, as well as asked if they’d spend real money on said satchel. For the other study group, they received information at night, given a night to “sleep on” their satchel selection, and then asked the same questions about their satchels of choice. The researchers hoped to discover if getting a night’s sleep between sessions impacted peoples’ opinions of their own earlier decisions, most likely by clarifying/confirming their choices.

Instead, they got a mixed bag of results. On the one hand, participants who’d slept on their decision liked their satchels more. On the other hand, that didn’t actually make them want to get them, suggesting that just because their feelings about their decision got stronger didn’t mean that those feelings would actually be converted into, well, making that decision.

Or, as the researchers put it: “Sleeping on a decision engendered more positive thoughts about the choice set. It might be assumed that this would make people feel better about their choice and more interested in pursuing it. However, counter to predictions based on previous literature, as well as common assumptions, sleep failed to improve perceptions of decision quality and indeed seemed to make participants more reluctant to consider commitment to the preferred item (e.g., spending money to purchase it).” While there’s definitely room to tighten the control elements of the study (for instance, what was the raffle bit about?), the study opens the door for a whole new take on decision influencing.

So, while you should still take your time making big decisions, it doesn’t seem like sleeping on it will actually do much. However, we’d err on the side of common sense and suggest that on the flip side, you shouldn’t make decisions while running low on sleep; after all, that’s how you end up buying random merch off of QVC at 3 in the morning.

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Image courtesy of Disney Animation.