Love is a profound euphoric feeling, a culturally universal phenomenon. From an evolutionary perspective, candid affection facilitates reproduction, good parental care, and material benefits. It also fulfills our sociality as a species: love-induced supportive interactions guard us against loneliness. But can the ecstasy of reciprocal romantic love provide you with more than this? Well several scientists have discovered that love can protect you from feeling physical pain.
A research group at the University of California in Los Angeles (UCLA) tested 25 women in long-term relationships. The participants endured uncomfortable 6-second thermal stimulations from heated probes on their forearms. At the same time they either held their partner’s hand, a stranger’s hand, or an object, or stared at pictures of their partner, a stranger, or an object. In each situation the women rated how unpleasant the heat felt. The scientists realised that both holding your partner’s hand and seeing an image of them had equally analgesic effects: participants reported feeling less pain! Somehow, being with their partner or thinking about them had prevented these women from experiencing the true intensity of unpleasant heat.
Dr Sean Mackey, a specialist in pain at the Stanford School of Medicine, and Dr Arthur Aron, a highly regarded expert in the science of love from the State University of New York at Stony Brook, built on this earlier analysis of behaviour by introducing neuroscientific techniques. Their seminal study examined 15 undergrads (men and women) that were in the early passionate period of a relationship with a functional magnetic resonance imaging (fMRI) machine. This device measures levels of deoxyhaemoglobin, blood without oxygen molecules, showing in real time where oxygen was being used in the brain and thus which areas were active.
As in the experiment in California, the students were subjected to mildly painful heat, while gazing at a photograph of their partner or an equally attractive acquaintance. Not only did participants report feeling less pain when staring at their partner, but neurological data from the brain scanner confirmed this: regions involved in experiencing physical pain showed decreased brain activation. However, Aron and Mackey also discovered that it was an increase in the activation of dopamine-rich reward systems, such as the nucleus accumbens, that seemed to be offsetting this activity in pain areas. These regions are heavily involved in all types of rewarding experiences, drug-use, and addiction. In fact, love had acted just like a pharmaceutical painkiller.
In a more recent study, the UCLA research group found that significant others function as a signal of safety to the brain during threatening experiences. As a result distress and physical pain is reduced. They examined 17 women in committed long-term relationships in an fMRI scanner, while they suffered uncomfortable heat stimuli and looked at various images. The initial results paralleled previous experiments, but with one difference: during the analgesic effects of a partner’s photograph, the ventromedial prefrontal cortex was active. This region is associated with safety signaling, reduced fear, and decreased threat responding. Increases in activity in this area were also correlated with longer relationship lengths: partners with greater levels of commitment signaled greater levels of security to the brain.
People say that love makes all your problems melt away, but now we know that love really can make us feel so euphoric that we are able to ignore pain. Mere photographs of your significant other are enough to provoke instinctive feelings of support and safety, and affect your physiological experiences. This may have evolved as an evolutionary advantage, enabling us to take action in the face of pain when we are with a loved one. Perhaps we are conditioned to feel good with them, regardless of the situation, because loving someone benefits the survival of the species.
Scientists believe that this research could lead to new methods of pain relief, without the side effects of drugs. Mackey even joked that he could start to “prescribe a passionate love affair”.