Old habits, both good and bad, are hard to break, suggests study of human memory

Nov. 11, 2004 -- No matter how hard we try to change our behaviors, it's the old ways that tend to win out over time, especially in situations where we're rushed, stressed or overworked, suggests a new study of human memory from Washington University in St. Louis.

"Our study confirms that the responses we learn first are those that remain strongest over time," says Larry Jacoby, Ph.D., a professor of psychology in Arts & Sciences at Washington University and co-author of the study.

A cup by any other name may still be a cup when our automatic memory gets involved, suggests a new study in the journal Psychological Science.

The study, titled "Which Route to Recovery? Controlled Retrieval and Accessibility Bias in Retroactive Interference," appears in the November issue of Psychological Science, a journal of the American Psychological Society. The research was conducted at Washington University by Jacoby and two other psychologists: Cindy Lustig, now at the University of Michigan, and Alex Konkel, now at the University of Illinois.

The findings are bad news for people struggling to change harmful behaviors, such as smoking or overeating, and good news for people who establish healthy lifestyles at an early age. Even when we consciously try to put new good intentions into place, those previously learned habits remain stronger in more automatic, unconscious forms of memory.

"We may try to change our ways, but after awhile, the response that comes to mind first is usually the first one we learned," Jacoby says. "If you learn the correct response in the first place, the passage of time will make you more likely to revert to that correct response."

The study suggests that over time, our bad habits (such as smoking) become automatic, learned behaviors. It also may help explain why when we're under stress we fall back into old habits, such as cheating on a new diet after a bad day at work. Stress can weaken our control over memory and behavior, so that those automatic, habitual responses from the past become more influential. With control weakened, those automatic responses — such as eating a cookie or smoking a cigarette — can override our new good intentions.

Aging can also erode aspects of memory that require control while leaving more automatic, learned behavior preserved. This latest research suggests that new learning requires control, whereas past habits are relatively automatic. This may help explain why it can be so hard for older adults to "learn new tricks" and maintain them over time, the researchers suggest.

Larry Jacoby

Is it a 'cup' or a 'mug'?

Participants in the study first learned one way of responding to a cue word (e.g., "Say 'cup' when you see 'coffee' "), and then later learned another way (e.g., "Now say 'mug' when you see 'coffee' "). They were given memory tests both immediately after learning the words, and the day after. Some people were told to control their memory and give only the first response ('cup'). Others were told to just give whichever response came automatically to mind.

Those controlling their responses did a good job of giving only the first response on both days. The interesting results were for the people who responded automatically, giving whichever response came to mind. On the first day, their answers were split evenly between the two possibilities. However, on the second day, they gave the first response ('cup') much more often than the second response ('mug'). The second response seemed to fade from memory, while the first response grew even stronger than it had been on the first day.

In their study, the researchers sought to take a new look at why old habits seem to prevail over our attempts to change our behavior. Their findings suggest that even though the strength of an old habit may fade over time, our memory for it will be stronger then any new good intentions that succeed it.

Psychological Science is ranked among the top 10 general psychology journals for impact by the Institute for Scientific Information. The American Psychological Society represents psychologists advocating science-based research in the public's interest.