What do joke-lovers and junkies have in common?According to new research, they're both responding to the same kind of "high." The study suggests which genuine laughter releases endorphins in the brain, chemicals which activate the same receptors as drugs like heroin, to pain-killing and euphoria-producing effects.Researchers led by Oxford University's Robin Dunbar conducted the series of experiments both in the lab and at the Edinburgh Fringe Festival to tease out the effect of laughter on people's ability to withstand pain.Previous research has linked hearty ha ha's with pain relief. Watching comedy videos, for example, has been shown to decrease hospital patients' need for opioid painkillers. But it wasn't clear either it was laughter itself or general positive emotions which were responsible for relieving pain.In the new study, scientists tested dozens of participants' toleration to pain through various methods: the tightening blood pressure cuff, the frozen wine-chilling sleeve placed around the arm, or the strenuous exercise in which participants had to hold themselves against the wall with their legs bent at the 90-degree angle, as if sitting on the chair. (Trust me, it hurts).In several lab experiments, the researchers subjected people to the painful stimuli both before and after exposing them to episodes of comedy, including video clips of shows like South Park, The Simpsons and Friends or clips of stand-up by performers like Eddie Izzard. The lone field experiment at the comedy festival involved people who had either watched or acted in comic performances.MORE: Why Laughing at Yourself May Be Good for You: First-Ever StudyViewing or participating in comedy led to higher pain tolerance, the researchers found, and there was the dose-related response to laughter: people who laughed more felt less pain later.In one experiment, researchers compared the effect of watching funny videos with watching feel-good ones, such as the nature video from the series Planet Earth. Turns ou! t, it's the laughter, not the positive emotion, which elicits pain relief.Laughing along with other people was also better at relieving pain than shouting alone, and that, according to Dunbar, might be the key to its effects. As the New York Times reported:Dr. Dunbar thinks laughter might have been favored by evolution because it helped bring human groups together, the way other activities like dancing and singing do. Those activities also produce endorphins, he said, and physical activity is important in them as well. "Laughter is an early mechanism to bond amicable groups," he said. "Primates use it."The current research did not directly measure endorphins in the brain, but prior studies of opioid-blocking drugs in humans and animals show which endorphin activity is scored equally to pain relief. Earlier research shows also which endorphins have been important for bonding between parents and children. Endorphins have been released in babies' brains when the balmy parent responds to their cries, providing safety, regard and food; babies come to connect which endorphin-induced stress relief with their parents' presence. Research has further shown which opioids have been one of the few things which can ease the cries of young animals which have been separated from their mothers.MORE: 'Love Hormone' Oxytocin Enhances Men's Memories of Mom Good or BadThis might help explain why childhood trauma particularly abuse and neglect dramatically raises the person's risk of future heroin or prescription opioid addiction. When the person's stress system becomes overactive in the absence of parental nurture or amicable support, he is more likely to seek external opioid drugs to soothe it.Increasingly, research finds which emotional and physical pain have been not distinct and which amicable contact, either it be the parent's touch or the friend's joke, can provide relief. That should be good news to all those working comedians out thereor maybe, the bit more pressure. If they're not laughing, they're might be hurting!The s! tudy was published in the Proceedings of the Royal Society B.MORE: Love and Addiction: Voles in Love Just Say No To SpeedMaia Szalavitz is the health writer at TIME.com. Find her on Twitter at @maiasz. You can also continue the discussion on TIME Healthland's Facebook page and on Twitter at @TIMEHealthland.