Should you buy the Bentley or the Rolls? The Audi or the Merc?
The second-hand Fiesta or the one previous-owner Micra? If you are struggling with such difficult decisions then Dutch researchers have the answer for you. Sleep on it.
A study by the University of Amsterdam shows that better decisions about complex purchases like cars and homes are made if you put aside the final choice and forget about it for a day or two.
They found that for simple choices it was usually better to apply conscious thought. For complex choices like cars, better results came from letting your unconscious mind mull over the options.
The research team published details of its 'Unconscious Thought Theory' last Friday in the journal Science. It all comes down to what they describe as the 'deliberation-without-attention effect'.
"Contrary to conventional wisdom, it is not always advantageous to engage in thorough deliberation before choosing," the Dutch team maintains.
They conducted four studies, some in the lab and some using real shoppers, to prove that 'sleeping on it', was a very good idea. In one they asked subjects to choose one of four hypothetical cars based on either a simple mix of four attributes or a complex mix of 12 attributes.
They forced the conscious thought group to decide which was the best car in four minutes. The 'unconscious thought' group were shown the attributes then the conscious parts of their minds were taken over for four minutes while doing anagrams before they made their decision.
The researchers found that conscious thinkers did better when the options were simple, but the unconscious thinkers did better when they were complex.
All of the studies pointed to the same thing, if the options are complex: "deliberation-without-attention" was the way to go.
"The more people thought consciously about simple products, the more satisfied they were with their purchase," the authors write. "Conversely, the more people thought consciously about complex products, the less satisfied they were with their purchase."
The team theorised that with a complex choice, conscious deliberation allows you to weigh up only a subset of the relevant information. In contrast, the human unconscious can integrate wider swaths of information.
So the next time you have to make the onerous choice between a Jag or a Beemer, put your feet up and take a nap and let your unconscious do the driving.