Why a good mood means bad decisions

LIZ HUNT

Health Editor

A good mood may be bad for people faced with problem-solving tasks that demand a high degree of logical thought and planning, according to a study.

Researchers say the brain may be too busy retrieving "feelgood" memories to enhance the positive mood to focus fully on the task in hand. Someone in a neutral mood can devote themself solely to problem solving, they argue.

A team from the Department of Psychology at Warwick University analysed the reasoning performance of individuals whose moods had been manipulated. To achieve a good mood, one group were shown a comedy programme; a neutral mood was triggered in another group by showing them a documentary; a bad mood was induced in a third group by showing them a documentary on stress. The groups were then given two reasoning tasks. The neutral mood group performed well, but the positive and negative mood states of the other two groups affected their performance.

In another test the groups were given a psychological test in which a block is moved around to achieve a given outcome. All three groups took the same time to plan the first move, but the good mood group then took twice as many moves as the others to attain the goal.

Dr Mike Oaksford, a senior lecturer in psychology, who will today present the results of the study on the opening day of the the British Psychological Society Conference in London, said: "The positive group put as much time into planning their first move as the other groups but their construction of a plan was much less efficient."

Dr Oaksford, who will receive the BPS Spearman Medal today for his work on human reasoning, said that the positive mood state may be affecting the brain's capacity for "working memory" - a space devoted to thinking, planning, and problem solving - as good memories are being retrieved at the same time.

"It is like a having a blackboard to work your problems out on but your memory is writing on that blackboard at the same time," he said.