Smart shoppers use unconscious tactics.

Consumers make better decisions about major purchases if they heed the power of their unconscious minds, say psychologist Ap Dijksterhuis of the University of Amsterdam and his colleagues.

Conscious thinking enables a person to follow precise rules using small amounts of information, the researchers say. Unconscious thinking, or deliberation without directing one's attention to the choice at hand, permits detection of critical patterns in a mass of information, Dijksterhuis' team asserts in the Feb. 17 Science.

In one experiment, 80 college students read information about four made-up cars. Each car was described by 4 or 12 attributes, including whether it handled well and got good gas mileage. One ear had mainly positive attributes, one had mainly negative ones, and two had even numbers of both.

When grappling with 12 attributes per automobile, students who were given 4 minutes to think about the cars and make a choice frequently didn't choose the best vehicle and immediately afterward said they were dissatisfied with the decision. Students who first spent 4 minutes completing the distracting task of solving anagrams usually chose the best cars and felt satisfied with the decision.

When volunteers had to consider only four attributes for each car, however conscious thinking proved slightly superior to unconscious deliberation.

Another experiment focused on 27 people making major purchases at a furniture store and 27 others buying inexpensive items at a department store. Those who reported having thought only a little about specific furniture to buy before shopping were much happier with their choices a few weeks later than were those who said that they had thought a lot about what to buy before shopping. The reverse characterized the department store customers.--B.B.