Study Suggests Why Gut Instincts Work

It seems that this works for complex decisions where there are many choices, or for small unimportant rescission. But there is also another article that says for normal decision (like buying a car, or renting a place), deliberate decision process is the best. http://www.livescience.com/culture/080811-decision-making.ht...

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In all experiments, there was some evidence that conscious deliberation can lead to better choices and little evidence for superiority of choices made "unconsciously," the researchers said.

Faced with making decisions such as choosing a rental apartment or buying a car, most participants made choices predicted by their individual preferences for certain features (for example, safety, security, color or price), regardless of the mode of thinking employed.

Unconscious decision-making was thought to be best in certain situations because it is not limited by how much stuff can be shuffled through the mind — a limitation thought to hobble conscious thought. And so, scientists had said the benefits of unconscious thinking are greatest when a decision is complex, with multiple options and attributes.

"Our research suggests that unconscious thought is more susceptible to irrelevant factors, such as how recently information has been seen rather than how important it is," Newell said. "If conscious thinkers are given adequate time to encode material, or are allowed to consult material while they deliberate, their choices are at least as good as those made 'unconsciously.'"