The team, led by Dr Mike Oaksford (now based at the University of Warwick), looked at the ways in which our mood can affect the quality of our analytical thinking. Dr Oaksford, a specialist in the field of human reasoning, has recently been awarded the Spearman Medal by the British Psychological Society for his non-mood-related work. He became interested in mood states after hearing about research carried out by the American psychologist Alice Isen at the University of Maryland. "She did a very interesting study on how positive mood, being happy, affects creative thinking, using a lovely task called Duncker's Candle Problem."
In this, the subject is given a small box of tacks, a box of matches and a candle, and told to attach the candle to the wall and light it in such a way that the wax doesn't drip on the floor. The solution is to empty the tack box, fasten it to the wall, and use it as a candle-holder. It is an exercise in lateral thinking, requiring a leap of insight rather than a series of logical steps. Isen found that subjects who were in a positive, happy mood were much better at solving the problem than people in either an emotionally negative or neutral state.
Prompted by Isen's findings, Oaksford and his colleagues set out to find what sort of effect mood states have on analytical thinking. Waiting to see what side of the bed volunteers had got out of was hardly a reliable method, so some means of putting them in the right mood was needed.
"Psychologists have induced mood states in a variety of ways," says Oaksford. "Hypnosis is one method, music another - usually short pieces that have been tested by musicologists for their elevating or depressing effect. Then there's something called 'Belton's Self Statements', where essentially someone sits there and says nice things about themselves for a while. Or they say negative things."
The method Oaksford chose, however, was the same as Isen's; he used short film clips that had previously been tested to ensure they had the desired mood-inducing effect. Clips from It'll Be Allright On The Night were used to induce a happy mood, while a clip from a documentary on stress brought about a more negative mood state. Two "neutral" mood control groups were also set up: one was shown an emotionally neutral film clip (from a David Attenborough natural history documentary), the other no film at all. "It was crucial that we had two control groups, because we wanted to make sure it wasn't just seeing a film that was having these effects," says Dr Oaksford.
Once they were feeling suitably good, bad or indifferent, the 62 subjects (mainly psychology undergraduates) were told to imagine they were immigration officials at an airport. The aim was to present them with a reasoning task as close as possible to something they might encounter in their day-to-day lives, in this case the enforcement of a regulation preventing anyone from entering the country without a cholera innoculation.
Using a variation of something called "Wason's Selection Test", they were shown four immigration forms from four different passengers. The catch was that they were shown only one side of each form, either the side that indicated whether the passenger intended to enter the country or was just in transit, or the side that contained a list of the passenger's innoculations. The task was to decide which of the four forms they needed to examine further, to ensure that the regulation wasn't being breached.
The correct response was to scrutinise only those forms that either didn't include cholera in the list of innoculations, or showed that the passenger intended to enter the country. If the passenger had either been innoculated, or was in transit, there was no problem and the forms could be discounted. The question was, did people perform this task any differently when they were in an induced mood state? Oaksford found they did. "The performance of the people in the neutral-film and no-film control groups was the same; reasonably good. Actually, it wasn't that good - but it was better than the negative- or positive-mood groups."
In fact 42 per cent of the control group subjects succesfully solved the problem, compared to only 21 per cent of the negative-mood group, and 9 per cent of the positive-mood group. Oaksford and his colleagues felt the likeliest explanation for this was something called "working memory" - the mental "workspace", where thinking and reasoning take place. "You can think of it like a mental blackboard, where you sit and do your working out. Mood states take up part of the space on the blackboard, space you need for some other task. It appears that mood states can act as 'recall cues' to memory, that some moods lead spontaneously to the recollection of memories."
When you are in a good mood, for example, the mood state itself triggers memories of happy (or "mood congruent") events. In the blackboard analogy, this amounts to someone sitting next to you saying, "Do you remember when... ?" and scribbling various recollections on the board while you're trying to work something out on it yourself. The space left for you to solve your problem is therefore reduced.
To test this hypothesis, Oaksford set the same "immigration" reasoning task as before. Instead of inducing a mood state in the subjects, however, they were given a second task to carry out at the same time (in this case monitoring a luggage-handling device, pressing one button if a red light showed, another if a green one lit). The intention was to see if the results of the first experiment could be replicated by distracting the subjects - thus occupying more of their working memory - instead of putting them into an induced mood state.
The results were identical. "We got exactly the same pattern as in the first experiment. Relative to the controls, who didn't have the distracting secondary task to perform, the subject's performance was impaired in the same way. It appears that a decrease in attentional resources produces impaired performance. What we then asked was, does this replicate across tasks? Could we take a task known to occupy working memory and show that mood also affects it?"
The task they chose was one known as "the Tower of London". Similar to a children's puzzle, it involves fitting three coloured blocks on to pegs of different heights (the first a single block high, the second two blocks, the next three). These have to be shifted from a starting configuration to a "goal" configuration in as few moves as possible.
The length of time it took subjects to plot their moves before starting was pretty much the same in all cases, regardless of mood state. There was also little difference in the average number of moves taken by the neutral control groups to complete the task (an average of 5.7 moves), and the negative-mood group (which averaged 6.7). The subjects in a positive induced mood, however, needed an average of 10.1 moves. So while being in a bad mood didn't have any significant effect in this instance, being in a good mood again made for a pretty poor performance.
"We can't really say much about negative mood," says Dr Oaksford, "because it doesn't seem to be a stable result. By comparison, the positive mood effect seems to be there whatever you do. It wasn't simply that the positive group were in a 'couldn't- care-less' frame of mind because they were happy. They took as long as people who were solving it in a reasonable number of moves. They were constructing plans, but their plans weren't as good as the other groups'."
The pattern Oaksford observed in subjects who were "distracted" by a positive mood state is in fact very similar to that found in patients suffering from damage to the frontal lobes of their brain - which is where working memory is thought to be located. In both instances the result is an impaired reasoning performance.
Oaksford is nevertheless quick to dispel the notion that being in a good mood is like having an instant lobotomy. "It doesn't mean that being happy is like having a bit of your brain removed, because clearly we are only looking at one task. There is a whole range of other tasks which happy people can perform with ease, which frontal lobe patients will find almost impossible. The empirical result happens to be the same on this particular task, but we're not saying these are identical phenomena. One is a very serious event; the other is not."
Dr Oaksford warns against drawing too many conclusions from what is, after all, only laboratory research. Even so, while a happy disposition may, according to the American research, be an advantage for creative tasks, the evidence so far does suggest that a good mood is far from beneficial for anyone relying on logic to solve a problem.
"If you're doing a bit of brainstorming," says Dr Oaksford, "it may be that getting in an upbeat mood is good for that. If you're involved in analytical tasks, then it may well be that being in a more neutral mood state is the best for you; you want to be cool, calm and collected. It's possible that different thinking skills have their own best mood state." !Reuse content