Children as young as seven are forming monogamous relationships which last for up to three years.
Many pre-adolescent boys and girls are keen to strike up romantic relationships, which elevate their status among their peers, according to Emma Renolds, a sociologist at Cardiff university.
She spoke to 59 children in two East Anglian primaries and found they greatly valued having a "boyfriend" or "girlfriend". They also regularly talked about "fancying", "going out", "being single", "snogging" and "being dumped".
In a paper to be given at Bera next week, Dr Renolds reveals the complex and sophisticated nature of such relationships, which, she estimates, about a fifth of primary pupils engage in.
One "couple", referred to as Todd and Sophie, began "going out" when they were in Year 3, aged seven. Their three-year relationship consisted mainly of sitting together in class, holding hands and kissing and they were regarded as the "official" couple of the school.
They were the most popular and romantically sought-after pupils and their romance broke up when their teacher put them in different classes to prevent them from "conducting a relationship beyond their years".
Another "couple", Pete and Mandy, became an item in Year 6, at the age of 10, and "went out" for about six months.
Pete wore baggy jeans, over-sized sweatshirts and trainers, Lynx aftershave and carefully styled his hair.
He achieved celebrity-like status and was bombarded with offers of girlfriends.
Childhood relationships which developed in the schools were fuelled largely by girls and the daily "gossip networks" through which they acted as matchmakers and messengers, said Dr Renolds.
She conducted her research from 1996 to 1999 and is presenting it at Bera for the first time.
Dr Renolds suggested teachers may overreact to infant romances. "Teachers often don't know how to interpret these relationships and are unsure about how to respond to them. Some teachers tend to over-sexualise what is happening and become concerned, which leads to them separating the children.
"In reality separation is not necessarily required as there is nothing sexual going on...and teachers and parents do not need to be concerned.
"Adults tend to interpret these relationships through adult eyes and that is not wise."
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