Keeping a stiff upper lip during an emotional event can impair your memory, research suggests.
Hiding emotions may cost memory
Those who battled to hide their emotions paid a cognitive price and were less able to recall the upsetting episode than others, a study found.
The work described in New Scientist involved more than 200 volunteers.
James Gross, Stanford University, and Jane Richards, the University of Texas at Austin, published their study in the Journal of Research and Personality.
They asked 57 volunteers to watch an emotive film about a surgical procedure and then asked them about how they were feeling, how much effort they put into hiding their emotions and how much they remembered about the film.
The people who said they had put the most effort into hiding their emotional response to the film had the worst recall for what they had seen.
The researchers then decided to test another 175 volunteers.
This time they asked half of the group to try to control their facial expressions to suppress their emotions while watching a film showing people arguing.
The other half were asked to distract themselves by thinking about something else as they watched the same film.
Both groups had similar difficulty recalling what they had seen.
Tim Dalgliesh, clinical psychologist at the Medical Research Council Cognition and Brain Sciences Unit in Cambridge, said this suggested that it was multitasking - trying to do two things at once - that caused the memory problem rather than simply controlling ones emotions.
"However, emotions can influence memory in very different ways," he said.
Stiff upper lip
We are better at remembering emotional material than non-emotional material, probably for survival reasons.
Emotions can also influence what information we recall. For example, being in a depressed mood might trigger us to remember past sad events.
Also, people in a highly charged emotional state tend to have poorer memory.
He said keeping emotions in check was not always a bad idea.
"It's all about balance. Sometimes it is good to suppress your emotions and it doesn't matter that there is a cost on memory because maybe allowing yourself to get upset might be worse.
"You might be in with your boss during your appraisal and he is saying terrible things and you feel like shouting and screaming with anger but you keep it in check because you would probably end up losing your job.
"You may not remember the details of what he was saying but maybe that is a good price to pay.