Walking with me are Gudberg Jnsson, a local psychologist, and Harvey Milkman, an American psychology professor. Twenty years ago, says Gudberg, Icelandic teens were among the heaviest-drinking youths in Europe. You couldn't walk the streets in downtown Reykjavik on a Friday night because it felt unsafe," adds Milkman. Young people aren't hanging out in the park right now, Gudberg explains, because they're in after-school classes ... or in clubs for music, dance, or art. Or they might be on outings with their parents. Today, Iceland tops the European table for the cleanest-living teens. The percentage of 15- and 16-year-olds who had been drunk in the previous month plummeted from 42% in 1998 to 5% in 2016. The percentage who have ever used cannabis is down from 17% to 7%. Those smoking cigarettes every day fell from 23% to just 3%. The way the country has achieved this turnaround has been both radical and evidence-based. If it was adopted in other countries, Milkman argues, the Icelandic model could benefit the general psychological and physical wellbeing of millions of kids. State funding was increased for organized sport, music, art, dance, and other clubs, to give kids alternative ways to feel part of a group, and to feel good, rather than through using alcohol and drugs, and kids from low-income families received help to take part. In Reykjavik, for instance ... a Leisure Card gives families 35,000 krona ($310) per year per child to pay for recreational activities.