Drinking and smoking are on the decrease among Australian teens. An author of the study, Professor John Toumbourou​, said while the adult population were also showing signs of moderating their alcohol consumption, it did not compare to the sharp trend within the secondary school population. "They are making changes that are much more dramatic to other age groups," said Professor Toumbourou, chair in health psychology at Deakin University. "It's a new, youth-led revolution." Lily Parsons, 13, explains it another way.

"It's not cool," she says. "If one of my friends drunk, I would try to stay away from them a bit." The year 8 student is from Colac, a town with a population of about 12,400 in south-west Victoria. Some things stay the same in Colac – it's still the sporty kids who occupy highest rung on the popularity ladder. But alcohol no longer appears to be as trendy as it used to be, at least for kids like Lily. Lily has read that it is safer to not to drink until after 21 – and she is going to "do her best" to abstain until then.

So, at the moment at least, her outings with friends involve shopping trips to Target, going to the movies and pool, and hanging out at "Maccas". Fifteen years ago it was her uncle, Ryan Fennell, roaming the streets of Colac looking for something to do. The financial advisor, now 31, says back then he did not think twice about the health effects of alcohol – it was either not talked about it, or it did not sink in. "If you weren't drinking, you were strange," he said. "You were a loser, I guess."

Ryan Fennell and his niece Lily Parsons, born 18 years apart, grew up in generations with differing views on teen drinking. Credit:Scott McNaughton His social life in Colac revolved around cricket, footy and hanging out with friends. "The weekends were focused around how we were going to get alcohol," Mr Fennell recalled. The newly published study, largely using Victorian data, found that in 1999 almost 40 per cent of surveyed students had favourable attitudes to substance use, compared to only 11 per cent in 2015. Meanwhile, only 10 per cent of surveyed teens had tried smoking tobacco in 2015, compared to 45 per cent in 1999. Just 4 per cent had tried cannabis, compared to 15 per cent in the older generation.

Professor Toumbourou believes changing parent attitudes are one of the major factors behind the moderating behaviour of their children. He said around the time of the Sydney Olympics some parents thought that it would be better to supervise teenagers drinking small or moderate amounts of alcohol, expecting they would drink anyway. Adam Golding, 31, was among this generation. He grew up in the Victorian regional city of Wodonga, and says he remembers his parents allowing him to bring two cans of beer to his friend's 15th birthday party. "Other times, getting a bit older, they said you can bring a bit more – maybe six drinks each." The technique, however, did not stop the teenagers drinking to excess anyway with alcohol obtained through other means.

Adam Golding, 18, with his friend Rob Glew, 17, at the Wodonga Races in 2004. Today, parents and teenagers are faced with evidence that drinking alcohol as a young person can cause permanent brain damage, including memory problems, because the brain only fully matures well into people's 20s. Loading Professor Toumbourou said parents may have been influenced by 2009 national guidelines recommending that teenagers abstain from alcohol altogether. He is among those calling for Australia's legal drinking age being raised to 21, in response to the scientific evidence of the damaging effect of alcohol on the growing brain.