New York:Adolescents living in neighbourhoods with more greenery may exhibit less aggressive behaviour, finds a new study. The findings showed that increasing greenery levels like parks, golf courses or fields, might lead to a 12 per cent decrease in clinical cases of aggressive behaviour. "Our study provides new evidence that increasing neighbourhood greenery may be an effective alternative intervention strategy for an environmental public health approach that has not been considered yet," said Diana Younan, doctoral student, at the University of California in the US. Nine to 18-year-olds who lived in places with more greenery had significantly less aggressive behaviour than those living in neighbourhoods with less greenery. Both short-term (one to six months) and long-term (one to three years) exposure to green spaces within 1,000 metres of residences were associated with reduced aggressive behaviour. The behavioural benefit of green spaces equated to approximately two to two-and-a-half years of adolescent maturation. In addition, these benefits existed for both boys and girls of all ages and races/ethnicities, and across populations with different socio-economic backgrounds and living in communities with different neighbourhood quality. "It is important that we target aggressive behaviours early. Identifying effective measures to reduce aggressive and violent behaviours in adolescents is a pressing issue facing societies worldwide," Younan added. Factors such as age, gender, race/ethnicity, socio-economic status, parents' educational background, occupation, income level, or marital status and whether their mother smoked while pregnant or was depressed did not affect the findings. For the study, the team followed 1,287 adolescents from Southern California who were aged nine to 18 years to see whether greenery surrounding the home could reduce aggressive behaviour. The results will be published in the forthcoming issue of the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP).