Before reading further, think of your phone number. If you are familiar enough with the number, you probably remembered it quickly.Yet you have no idea how your brain worked this magic.
That is, you do not have direct access to the neural or cognitive processes that lead to your thoughts and behaviour.You thought about your phone number, and (if the magic worked) the num-ber popped into your consciousness.
This brief exercise illustrates a central property of consciousness:
We are aware of some mental processes and not aware of others. Over the last several decades, many researchers have explored different ways in which unconscious cues, or subliminal perception,can influence cognition. Subliminal perception refers to stimuli that get processed by sensory systems but, because of their short durations or subtle forms, do not reach consciousness. Advertisers have long been accused of using subliminal cues to persuade people to purchase products (FIGURE 4.11).The evidence suggests that subliminal mes-sages have quite small effects on purchasing behaviour (Greenwald, 1992), but material presented subliminally can influence how peo-ple think even if it has little or no effect on compeo-plex actions. (Buying something you did not intend to buy would count as a complex FIGURE 4.11 Try for Yourself: Subliminal
Perception
Answer: The ice cubes spell out S-E-X.
Try to pick out the subliminal message in the advertisement below.
subliminal perception Information processed without conscious awareness.
action.) That is, considerable evidence indicates that people are affected by events—stimuli—they are not aware of (Gladwell, 2005). In one recent study, par-ticipants exerted greater physical effort when large images of money were flashed at them, even though the flashes were so brief the participants did not report seeing the money (Pessiglione et al., 2007).
The subliminal images of money also produced brain activity in areas of the limbic system, which is involved in emotion and motivation. Subliminal cues may be most powerful when they work on people’s motivational states. For example, flashing the word thirst may prove more effective than flashing the explicit directive Buy Coke. Indeed, researchers at
the University of Waterloo found that subliminal presentations of the word thirst led participants to drink more Kool-Aid, especially when they were actually thirsty (FIGURE 4.12;Strahan, Spencer, & Zanna, 2002).
Other events can influence our thoughts without our awareness. In a classic experiment by the social psychologists Richard Nisbett and Timothy Wilson (1977), the participants were asked to examine word pairs, such as ocean-moon, that had obvious semantic associations between the words.They were then asked to free-associate on other, single words, such as detergent. Nisbett and Wilson wanted to find out the degree, if any, to which the word pairs would influence the free associations—
and, if the influence occurred, whether the participants would be aware of it.When given the word detergent after the word pair ocean-moon, participants typically free-associated the word tide. However, when asked why they said “tide,” they usually gave reasons citing the detergent’s brand name, such as “My mom used Tide when I was a kid”; they were not aware that the word pair had influenced their thoughts.
Here again, the left hemisphere interpreter was at work, making sense of a situation and providing a plausible explanation for cognitive events when complete informa-tion was not available. We are, of course, frequently unaware of the many different influences on our thoughts, feelings, and behaviour. Similar effects underlie the clas-sic mistake called a Freudian slip, in which an unconscious thought is suddenly expressed at an inappropriate time and/or in an inappropriate social context.
Another example of unconscious influences’ power comes from the work of Yale University’s John Bargh and his colleagues (1996), who asked participants to make sentences out of groups of words. Some of these words were associated with the elderly, such as old, Florida, and wrinkles. After the participants had made up a number of sentences, they were told the experiment was over. But the researchers continued observing the participants, interested in whether the unconscious acti-vation of beliefs about the elderly would influence the participants’ behaviour.
Indeed, participants primed with stereotypes about old people walked much more slowly than did those who had been given words unrelated to the elderly. When questioned later, the slow-walking participants were not aware that the concept of
“elderly” had been activated or that it had changed their behaviour. Other researchers have obtained similar findings. For instance,Ap Dijksterhuis and Ad van Knippenberg (1998) found that people at Nijmegen University, in the Netherlands, better answered trivia questions when they were subtly presented with informa-tion about “professors” than when they were subtly presented with informainforma-tion about “soccer hooligans,” although they were unaware that their behaviour was influenced by the information. Such findings indicate that much of our behav-iour occurs without our awareness or intention (Bargh & Morsella, 2008;
Dijksterhuis & Aarts, 2010). and won). The cues related to thirst led the participants to drink more liquid.
THE SMART UNCONSCIOUS Common sense tells us that consciously thinking about a problem or deliberating about the options is the best strategy for making a decision. Consider the possibility that not consciously thinking can produce an outcome superior to that of consciously thinking. In a study by Ap Dijksterhuis (2004), participants evaluated complex information regarding real-world choices—
for example, selecting an apartment. In each case, the participants chose between alternatives that had negative features (e.g., high rent, bad location) and positive features (e.g., nice landlord, good view), but objectively, one apartment was the best choice. Some participants were required to make an immediate choice (no thought); some to think for three minutes and then choose (conscious thought);
and some to work for three minutes on a difficult, distracting task and then choose (unconscious thought). Across three separate trials, those in the unconscious thought condition made the best decisions. According to Dijksterhuis and Nordgren (2006), unconscious processing is especially valuable for complex deci-sions in which it is difficult to weigh the pros and cons consciously.A similar phe-nomenon has also been reported in the creativity literature: Anecdotal reports suggest that allowing an idea to incubate over time helps in problem solving.
Perhaps this is why, for very important decisions, people often choose to “sleep on it.” (Chapter 8, “Thinking and Intelligence,” will return to this idea in discussing problem solving strategies.)
Consider also the possibility that consciously thinking can undermine good deci-sion making.The American social psychologist Tim Wilson and the American cog-nitive psychologist Jonathan Schooler (1991) asked research participants to rate jams.
When the participants simply tasted the jams, their ratings were very similar to experts’
ratings. However, when the participants had to explain their ratings jam by jam, their ratings differed substantially from the experts’. Unless the experts were wrong, the participants had made poorer judg-ments: Having to reflect consciously about their reasons apparently altered their perceptions of the jams. Schooler has introduced the concept of verbal overshadowing to describe the perform-ance impairment that occurs when people try to explain verbally their per-ceptual experiences that are not easy to describe (Schooler & Engslter-Schooler, 1990; Schooler, 2002). For example, participants who had to describe the perpetrator they saw in a simulated bank robbery were less able to pick the person out of a lineup than were par-ticipants who did not have to provide a description. The descriptive labels used by the first group altered those participants’ memories of the robber. In another study, participants who had to describe a wine’s taste were later less able to detect that wine’s taste than were participants who simply tasted the wine and did not describe the taste (Melcher
& Schooler, 1996). Consciously reflect-ing on the wine’s qualities impaired FIGURE 4.13 Try for Yourself: Verbal Overshadowing
Pick the image below that is by a famous painter.
Now explain why you chose the image you did.
If you are like most people, you found it difficult to verbalize your perceptual experience.
Answer: Untitled XX, on the right, is by Willem de Kooning (1904–1997), consider ed a
master of abstract expressionism. The painting on the left, Lollipop House, was painted
by Marla Olmstead (b. 2000), the subject of the 2007 documentary My Kid Could Paint That.
performance.The take-home message of these studies is that we are not very good at describing perceptual experiences; when we are forced to do so, the act of ver-bally labelling alters our memories.Although it is unclear exactly why thinking too much can impair judgment and memory, some things appear to be best left unsaid (FIGURE 4.13).