Psychologist Eva Vass of the Open University observed 26 Year 4 pupils at two schools during creative writing classes and found that pairing was beneficial.
She judged the pairings' effects on creative work by referring to the teacher's assessment, the coherence and use of language and the pupils' own feedback on the work.
"Friendship pairing is a good thing on the whole, although it depends on the particular friendship," Ms Vass said. "People who don't consider themselves friends may grow closer during these activities, but initially there are quite significant differences between friends and non-friends. This is because of the intimate process of creativity - it's easier with someone you are close to and have shared experiences with.
"Emotional aspects of paired work have mostly been ignored by studies on collaborative learning," she added. "So we hope to help teachers realise the potential benefits of working with a partner."