The newest development in understanding human calmness after conflict comes from research from the University of Granada, which reveals that blue lighting "accelerates post-stress relaxation," according to a study published in PLOS ONE this week. The scientists used 20 healthy volunteers who were put in a stressful scenario: they had to do the Montreal Imaging Stress Test, which stresses people out by making them do swift arithmetic while being observed by others. Afterwards, the volunteers were put in relaxation sessions in "chromotherapy" rooms, one with blue light, and one with white.

"The blue lighting accelerates the relaxation process after stress in comparison with conventional white lighting," the scientists noted, with people in the blue room feeling more relaxed and showing calmer physiological reactions within 1.1 minutes, as compared to 3.5 minutes in the white room. After about 3.5 to 5 minutes, the advantage of the blue room disappeared and everybody's reactions evened out, but the dose of blue light appeared to give stressed people a jump-start on calmness.

This is old hat for anybody who's been calmed down by others, but we actually haven't fully understood why it works until recently. In 2017, a study published in Science honed in on why deep breathing has a calming effect on the brain. A collection of American scientists have identified what they've called the "pranayama neurons," after the practice of regulating your breath as part of meditation. They're 175 specific neurons found in mammal brains that appear to link our actual breathing patterns and our emotional state of mind. When the scientists "knocked out" the neurons in the brains of mice, they found that the mice became very calm and quiet and breathed very slowly, and that it seemed to have broken a chain between the parts of the brain that register breathing patterns and those that translate that into arousal or anger. Doing slow deep breaths, it seems, enacts physical changes in the brain that help shift your emotional state.

Music may soothe the savage beast, but if you've ever wondered if it's possible to hear the "calmest song in the world", you can — sort of. According to the research institute Mindlab International, which conducted a study on behalf of a bath and shower gel company, they've managed to create the most relaxing song ever, in collaboration with the musical group Marconi Union. The song, called "Weightless," has a rhythm of 60 beats per minute, which apparently results in breathing and heartbeat synchronizing and slowing, and also involves bass and "low whooshing sounds." When played to 40 women, Mindlab says, the song produces a 65 percent reduction in anxiety levels and a 35 percent reduction in physiological resting rates. It's important to remember that this music was part of a PR campaign and nobody has duplicated the results, but the song is indeed quite calming to listen to, in my experience.

Got some whale sounds on CD? A bird sanctuary nearby? A river you can go sit beside? If you're angry or stressed, scientists recommend nature sounds as a good way to enter a calmer space. Research from 2017 done by the University of Sussex reveals that when people are exposed to sounds from natural environments, the signals of stress and arousal in their bodies visibly reduce. They exposed subjects to noises from natural places and artificial environments while monitoring their brain activity and their heart rates, and found that brain activity shifted significantly depending on the sounds. Natural noises made people's brains look "outwards," listening and being aware of their environment, while artificial noises made people ruminate, stress, and think "inwardly." The bodies of people listening to natural sounds also relaxed more, though the results were the most marked in people who were very stressed. If people were very chilled out when they came into the experiment, natural noises actually made them slightly more aroused and stressed — so if you're already feeling very calm, it's possible an hour of bird noises isn't for you.

The practise of aromatherapy — how scents affect human cognition and behavior — is often seen as a bit unscientific, but there's actually quite a bit of science around trying to pin down our reactions to different smells. While a lot of it is still up in the air, two particular scents, rosemary and ylang ylang, have given repeated results showing that they may influence stress reduction in healthy adults. Lavender has been shown to reduce anxiety and stress levels in studies — one in 2016 showed that it calmed elderly people, another in 2017 that it's relaxing for horses — and ylang ylang has showed itself to be calming on human blood pressure and heart rate, arousal levels, and general levels of anxiety if applied to the skin as an oil. If that's your bag, get to an aromatherapy shop pronto.

If you're the kind to scrub the floors, throw things out, or sort all your CDs when you're angry, that may actually be a very good plan for lowering your stress levels. A study by Florida State University in 2015 found that "mindful" activity doing chores — specifically the act of doing the dishes — was actually a good stress reliever. Mindfulness means awareness of what you're doing and feeling in the moment, and the scientists behind the study of 51 college students found that students were more capable of "washing the day away" if they paid attention to their chore as they were doing it, attempted to focus and enjoy the process, and didn't spend the time thinking of other things or negative emotions. The students who were mindful reported that their nervousness decreased by 27 percent from the process. It's important to remember that this is one study with self-reported results (they weren't hooked up to MRIs or machines measuring heart rate while they rinsed the dishes), but it's an indication that doing a mindful activity might not be the worst idea when upset.

If you're really pissed off, a psychological trick may help you get out of that space and move towards a resolution: self-distancing. Self-distancing means separating yourself from the problem by imagining that it's happening to somebody else you care about, like a best friend. A study in 2014 revealed that when people do this after being asked to imagine they've been cheated on, they're able to approach the situation with more rationality. And it's also been proven to help people in situations where they're feeling aggression and serious negativity.

One study in 2012 found that pretending a situation is happening to somebody else works to dampen aggressive reactions, while another in 2015 focussed on teens and young people found that self-distancing was a way to help them cope with negative emotions and look at upsetting events with insight. If you play out the argument as if it's happening to your friend Sharon, rather than to you, it will likely help you calm down and gain some perspective.

Sometimes, of course, all of the blue light, whale sounds and chores in the world won't stop you being angry. In those cases, it's better to let it out, in a safe and healthy way, rather than attempt to keep it in. But if you just need five minutes to feel less like a rage-monster, keeping some of these tricks on standby might help you chill out a little.