We may have found the key to marital peace. It’s green, it’s pungent, and it’s the cause for nearly 1 million arrests every year. The notion that people who smoke weed are non-violent peace lovers may be more than just a stereotype. A new study in the journal Psychology of Addictive Behaviors has found that couples that smoke weed together have staggeringly lower levels of domestic violence. Couples where both spouses smoked at least a few times a month — which was the highest end of the researchers’ scale — had the lowest levels of violence in the study. The study looked at 638 newly-wedded couples over the course of 9 years. The couples each did an initial interview and then subsequent interviews after one year, 2, 4, 7, and then 9 years. Part of the data collection included reporting their marijuana usage and instances of aggression within the relationship. The researchers say that this means marijuana use can help predict violence levels over the next year – but they don’t know if smoking weed has the power to influence violence levels on any given day. The sample is also limited to straight couples in their first marriage. Of course, the temptation is to jump to the conclusion that weed makes people more peaceful – but there may be other reasons why this connection exists. They’ll need to do more research to know for sure. One reason that couples that smoke together are more peaceful may because they’re more likely to share core values and social circles, making them less likely to fight. The researchers also describe the possibility of a “positive effect” – which is basically science-speak for “people feel happy when they’re high so they’re less likely to fight.” Another mechanism on the table builds on previous research – we know that marijuana users have dulled reactions to threats and aggression, making them less likely to initiate aggressive behavior. What’s even more interesting is that this study was funded in part by the National Institute for Drug Abuse – an institution that is well-known for it’s strong position against recreational marijuana use. The study adds to the growing body of research about the effects of marijuana on individuals, their relationships, their lives and work. Here in the US, we really are amidst a giant green flurry. Some of you may recall last year the New York Times did a huge marijuana issue which called for legalization on the front of the Sunday paper in big, bold letters. About half the country now allows medical marijuana with a prescription, in 2 states it’s fully legal. Researchers are watching Colorado like a hawk – AND the federal government has upped its marijuana research quota. Now they’ll be growing 650 kilograms of weed. Last year they grew 21. I expect the research will continue to avalanche in the coming months and years and perhaps more policies will be changing in response.