Children as young as four are being introduced to street and gang culture in parts of Glasgow, according to research.

Johanne Miller, of the University of the West of Scotland, said children in the Scottish city may be fully fledged gang members who accept violence as "part of their lives" by the age of 12.

Miller, who spent weeks studying 60 members of 21 gangs in Glasgow, said the groups formed in the city are not hierarchical, organised criminal groups but merely friends who have grown up close to each other.

She said: "The process that emerged from participants was that young people aged between four and 12 began playing in the few streets that made up their scheme – a council-built estate – and began from a young age to be socialised into street culture.

"These children have grown up hearing stories of territorial rivals and the crimes they enact.

"So within the child's conscious there is a known enemy, an 'other' out there who is already a threat in their minds. There is a tradition of associating your scheme as something that needs to be protected."

She added: "They would begin absorbing street culture transmitted through story-telling and observations of older children in the area and family members. They would adopt the gang name, start using it and decide whether they wanted to fight or not. This is how they grew into the gang. This violence then becomes more serious for core members, and conflict becomes a central binding agent of the gang."

Miller said her research showed that when aged between 14 and 18, gang members could spend as much as six hours a day on the street and even more at weekends.

She said gangs usually occupy derelict buildings and parking lots as well as forests, with fighting taking place away from CCTV and regular police controls.

"I was told stories about broken arms, a broken back from falling from a cliff, nails through feet, being hit with cars, someone being set on fire, suicides, shootings, stabbings, a boy's brother buzzing gas and it blowing up, killing him," Miller said. "People being hurt and dying was an accepted part of their lives, it was just another inevitable part of occupying the streets for the young people."

However, Millar described how most members only stay in a gang for around three years before "drifting away".

A Scottish Government spokesperson said: "There are relatively low numbers of young people involved in gangs in Scotland.

"Our approach to divert young people from offending is based on prevention, early intervention and providing appropriate support. Our early intervention initiative – the whole system approach – tackles all aspects of youth offending from low-level crime to the most serious and harmful offences and aims to stop young people following the wrong path."