Parents all over Iceland’s capital embark on a two-hour evening walk around their neighbourhood every weekend, checking on youth hangouts as a 10pm curfew approaches.
The walk in Reykjavik is one step toward Iceland’s success into turning around a crisis in teenage drinking.
Focusing on local participation and promoting more music and sports options for students, the island nation in the North Atlantic has dried up a teenage culture of drinking and smoking.
Icelandic teenagers now have one of the lowest rates of substance abuse in Europe.
Other countries are taking notice.
The Icelandic Centre for Social Research and Analysis, the institute pioneering the project for the past two decades, says it currently advises 100 communities in 23 countries, from Finland to Chile, on cutting teenage substance abuse.
“The key to success is to create healthy communities and by that get healthy individuals,” said Inga Dora Sigfusdottir, a sociology professor who founded the Youth of Iceland programme, which now has rebranded as Planet Youth.
The secret, she says, is to keep young people busy and parents engaged without talking much about drugs or alcohol.
That stands in sharp contrast to other anti-abuse programmes, which try to sway teenagers with school lectures and scary, disgusting ads showing smokers’ rotten lungs or eggs in a frying pan to represent an intoxicated brain.
“Telling teenagers not to use drugs can backlash and actually get them curious to try them,” Ms Sigfusdottir said.
In 1999, when thousands of teenagers would gather in Reykjavik every weekend, surveys showed 56% of Icelandic 16-year-olds drank alcohol and about as many had tried smoking.
Years later, Iceland has the lowest rates for drinking and smoking among the 35 countries measured in the 2015 European School Survey Project on Alcohol and Other Drugs.
On average, 80% of European 16-year-olds have tasted alcohol at least once, compared with 35% in Iceland, the only country where more than half of those students completely abstains from alcohol.
Denmark, another wealthy Nordic country, has the highest rates of teenage drinking, along with Greece, Hungary and the Czech Republic, where 92% to 96% have consumed alcohol.
In the US, teen drinking is a significant health concern, because many US teenagers are driving cars and do not have access to good public transport like teenagers in Europe.
The US Centres for Disease Control reports that while US high school drinking has declined substantially in the last 20 years to 32.8% in 2015, 17.7% of U.S. high school students still binge drink at least once a month.
The CDC also reports that excessive drinking accounts for around 4,300 deaths a year in the US among people under 21.
Reykjavik mayor Dagur B. Eggertsson said the Icelandic plan “is all about society giving better options” for teens than substance abuse.
He believes the wide variety of opportunities that now keep students busy and inspired has dramatically altered the country’s youth culture.
Yet better options cost money.
Local municipalities like Reykjavik have invested in sport halls, music schools and youth centres.
To make the programmes widely available, parents are offered a 500 US dollar annual voucher toward sports or music programmes for their children.
As a teenager, Mr Eggertsson remembers taking the bus on weekend nights to wander the streets of Reykjavik “without really going anywhere”.
“I remember watching a friend puke behind a police station and fishing another one from the harbour after falling in,” the 46-year-old father of four said.
“What was socially acceptable then would now be a scandalous headline in the paper.”
Today’s news articles about teenagers have a different tone.
Anxiety and symptoms of depression have never been higher, particularly among girls, where the rate has doubled in the past 10 years.
Vaping has replaced tobacco use, with about 40% of Icelandic 16-year-olds having tried the electronic cigarettes.
Researchers say the Planet Youth prevention model is evolving constantly because it is based on annual surveys to detect trends and measure policy effectiveness.
The group of parents patrolling the Korar neighbourhood, a lawyer, an advertising agent and a diplomat, among others, walk across empty car parks to pass by known teenage hangouts.
By law, introduced when Icelandic police routinely dealt with alcohol-fuelled street gatherings, children under 12 are not allowed to be outside after 8pm without parents and those 13 to 16 not past 10pm.
Over summer, when school is out, the curfew is extended by two hours.
“We tell the kids if they are out too late, polite and nice, and then they go home,” said Heidar Atlason, a veteran member of the patrol.
Over Iceland’s harsh winter, the one parent admits, evenings sometime pass without running into any students.
Modern teenagers meet online rather than outside.