For centuries, humans have been thinking about thinking. In the early 1600s, Rene Descartes famously asserted cogito ergo sum, “I think, therefore I am.” In the late seventeenth century, John Locke was among the first to write about consciousness. But while philosophy books are thick with such exquisite reflections on human cognition, we are left to speculate as to whether Descartes’ ruminations helped him reliably choose good bottles of wine, or if Locke’s deliberations left him satisfied with the shoes he decided to wear. Recent research by Loran Nordgren (Management & Organizations) and his colleagues Ap Dijksterhuis, Maarten Bos, and Rick van Baaren of Radboud University Nijmegen adds some surprising insights to our understanding of thought and its influence on decision making. Published in Science, the work highlights the value of unconscious thought, suggesting that when it comes to complex decisions, many of our best choices are made in the absence of attentive deliberation. Contrary to conventional wisdom, there are times when we might be better off tossing the spreadsheets with lists of pros and cons and just switching on autopilot.

“I’m interested in the boundaries of unconscious processes in the mind,” said Nordgren. “We readily accept that most behavior is driven by mental events that we have no access to. Our heart beats. We pick up a cup or type on a keyboard. All are complicated tasks, but we have no idea how they happen. It takes place in a black box; we have no access to it.”

“But we imagine that those unconscious processes stop at basic behavior,” he continued, “that more complex, higher-order processes are surely driven by our conscious selves. Whether to marry, what job to take, are these the products of conscious machinations of the mind, or processes that we have no access to? It doesn’t need to be a pure dichotomy. But dominant thinking hasn’t been open to this idea.”

Arthur Schopenhauer is thought to have been the first to propose unconscious thought, writing in the mid-1800s that perhaps half of all thought occurs without us ever knowing about it. But while thoughts about thought have evolved across generations, one belief in particular has remained relatively widespread and unchanged: to make sound decisions, people must consciously, deliberately, weigh their options. Nordgren and his colleagues are challenging that belief.

“What is consciousness good for?” asked Nordgren. “Lots of animals make complex evaluations like we do. Some people grant animals consciousness, but many others don’t. So my suspicion is that consciousness, introspection, while very unique, may not do all that we think it does.”

Conscious thought is like a spotlight on a decision. It illuminates very brightly, but only a particular, narrow aspect of the problem. Unconscious thought, on the other hand, is more like a child’s night light, casting a dim light on the entire decision space without focusing in on any one particular thing.

Conscious Deliberation has Limitations

Nordgren and his colleagues caution against a one-size-fits-all strategy toward decision making. Conscious decision making certainly has its advantages and is not without its place. Math, for example, cannot be performed without paying close attention, because consciousness goes hand in hand with precise, rule-based thinking. Thus, humankind’s stunning advances in fields like science and engineering depend on healthy doses of conscious calculation. However, the researchers’ results indicate that consciousness has limited capacity, and only a fraction of the relevant information can be considered for very complex decisions. Moreover, conscious deliberation has been shown to inflate the importance of certain features at the expense of others, distorting the outcomes.

Explained Nordgren, “Conscious thought is like a spotlight on a decision. It illuminates very brightly, but only a particular, narrow aspect of the problem. It has very limited processing capacity. Unconscious thought, on the other hand, is more like a child’s night light, casting a dim light on the entire decision space without focusing in on any one particular thing.”

Recent studies show that in certain cases, people who make such “night light” decisions without investing too much conscious thought come to more satisfying conclusions. Alternatively, consistent satisfaction with choices has been shown to suffer if too much “spotlight” attention is paid to the decision-making process. Inspired by this growing body of research, Nordgren and his colleagues propose their “deliberation-without-attention” hypothesis. As the name suggests, this attempts to describe our ability to mull options and make decisions without awareness that we are doing so.

The authors predicted that the complexity of a decision would dictate whether a conscious or unconscious strategy of thought should be employed. To explore the relationships among these variables, the researchers conducted a series of experiments, each of which involved people consciously or unconsciously making simple or complex decisions.

The researchers first asked several dozen people to pretend they were car shopping. Half of the participants read brief descriptions of four cars that were considered “simple,” because only four features were discussed. Some features were good (e.g., “The Dasuka has good mileage”), others bad (e.g., “The Kaiwa has little legroom”). The second half of the participants read about four cars that were “complex,” because twelve features were discussed instead of a mere four. In each list of cars, one car was described positively on 75 percent of its features, two cars were good and bad in equal measure, and one car was described negatively for 75 percent of its features.

Half of the participants in each group were then asked to think intently about the cars in anticipation of eventually rating them. The other half were told that they, too, would have to eventually rate the cars, but they were then immediately distracted and asked to solve word puzzles in order to prevent them from consciously reflecting on transmissions, stereo systems, and other car features. After four minutes of contemplation or word games, people were asked to pick one, favorite car, or to rank all four cars on a scale ranging from “very negative” to “very positive.”

Unconscious Decisions Have an Edge in Complex Problems

The results were clear. Conscious deliberation helped identify good cars when the cars were relatively simple. However, when the cars were more complex, the distracted people made the better choices. They identified the best cars even though their decision-making process took place “below the radar” of their conscious attention as they wrestled with word games.

Encouraged but still curious, Nordgren and his colleagues wanted to push their deliberation-without-attention hypothesis further. He asked, “How well does this extend outside the lab?”

Knowing that a make-believe shopping spree does not necessarily tell us how life’s real decisions are made, the team asked people to rank forty actual products according to the number of key features they would consider when buying each item. Cars and computers topped the list, averaging around five to nine important features, while umbrellas and dishwashing brushes were simplest, having only one to three influential features. Other people were then asked about items on the list that they actually bought: “How much did you think about the product between seeing it for the first time and buying it? How satisfied are you with the product?”

Echoing the lab-based study of car buyers, these real findings showed that customers who focused intently on a purchase were more satisfied when they bought simple objects. Complex items were enjoyed most by those who did not put a lot of conscious thought into the decision.

The authors arrived at similar results when they interviewed shoppers from two stores: Bijenkorf, a Dutch store that sells clothes and small accessories, and IKEA, a Swedish purveyor of home furnishings. When contacted several weeks later, customers were more satisfied with their purchases of complex products such as sofas and desks when they unconsciously arrived at their decisions, and customers were happier with their purchases of simple products such as towels and detergent when they made their decisions consciously.

Having validated the theory both in the lab and in the field, Nordgren is enthusiastic about the potential to apply this research. “We have consumer data,” he said, “but we want more than that. Different levels of experience and expertise may be important in different ways. We’re now working on medical decision making, looking at executive decision making.”

He continued, “Usually, research about decision making is descriptive. But there’s a prescriptive aspect to this work. How do you go about making a good decision? For unconscious thought to work, it needs to be goal directed. You need to form an intention to work on a problem, and then divert attention elsewhere. It’s all about intention and trust. Form the intention to work on the problem, and then trust the part of you to work on it.”