A review of non-fiction writing for pupils from seven to 14 said argumentative essays were being overlooked in favour of fiction or literary exercises.
Academics from York university say that non-fiction is seen as a poor relation of fiction. They say there should be equal emphasis on discursive or argumentative writing.
The report said: "Argument has an important part to play in the history lesson, for example, or the science laboratory. Pupils might be taught how to use a discursive marker, such as the word 'however', within a sentence.
They might be encouraged to learn and consolidate argumentative strategies - alliteration, facts, opinion, repetition or emotive language."
It called for more emphasis on planning essays and organising and evaluating ideas before putting pen to paper and said oral argument and counter-argument, should inform discursive writing.
The report encouraged teachers to be able to show good discursive writing.
It said: "The age group from seven to 14 appears to be an important one for such studies as this is the period during which argumentation can be developed."
Sue Palmer, literacy consultant, said primary teachers often overlook non-fiction because of an emphasis on writing fiction in national tests but that this emphasis is now shifting.
"How many people need to write a story in real life?" she said. "It's nice, but it's not essential. It's not a life skill. But being able to argue your case is a life skill. Story writing is a way for children to express themselves. But you can teach technique in non-fiction: construction of sentences, stylistic devices. It gives you particular linguistic structures. Those skills make you a better speaker as well."
Paul Wagstaff, director of the primary national strategy, said equal emphasis was given to fiction and non-fiction writing. He said: "We have always suggested a balance across a range of genres. We want to ensure that children have skills and are completely confident in both styles."
primary forum 18 website: eppi.ioe.ac.uk