Why Some People Hurt Themselves to Feel Better: Scientists Find a Clue

Researchers at Harvard University have found a new clue about why some people hurt themselves on purpose. They were studying a behavior called non-suicidal self-injury, or NSSI. This means hurting yourself — like cutting or burning your skin — without wanting to die. About one in five teenagers worldwide has done this at some point, making it a serious health concern.

The big puzzle scientists wanted to solve was this: why does physical pain sometimes make people feel emotionally better? That seems to go against common sense, since pain is supposed to feel bad. But many people who self-injure say they feel calmer or less distressed after doing it. Scientists think this may be because the brain uses some of the same pathways for physical pain and emotional pain, so one can actually reduce the other.

The research team focused on an idea called 'intuitive Dualism.' This is the natural human feeling that the mind and the body are two separate things. Most people feel this way without even thinking about it — we tend to think our thoughts and feelings are different from our physical bodies, even though the brain controls everything. The researchers wondered if people who self-injure might think about this mind-body connection differently.

To find out, the scientists recruited two groups of young adults aged 18 to 40. One group had a history of self-injury, having hurt themselves at least five times. The other group had never self-injured. Everyone completed an online study that included a special thinking task about minds and bodies.

In the task, participants imagined two situations: one where a perfect copy of a person's body and brain was made, and one where a person died but their mind lived on in an afterlife. They were asked whether the person's thoughts, emotions, and actions would still exist in each case. This helped the researchers figure out whether each person leaned toward seeing mind and body as separate (Dualism) or as basically the same thing (Physicalism).

The results showed that people with a more severe history of self-injury — meaning they had hurt themselves many more times — leaned more toward Physicalism. They were more likely to believe that copying the body would also copy the mind. The researchers think this blurring of the mind-body divide may make it harder for these individuals to recognize and understand their own emotions.

The study also found that people with more severe NSSI who leaned toward Physicalism had a harder time explaining why they self-injured. They were less likely to point to clear emotional or social reasons. This fits the idea that when someone struggles to tell the difference between physical feelings and emotional feelings, understanding their own behavior becomes harder too.

The researchers are careful to say this study is just a first step. The group studied was small, and the findings only show a connection — not a cause. It is still unknown whether a blurred mind-body divide leads to self-injury, or whether self-injury changes the way a person thinks about minds and bodies. More research is needed to answer that question.

Even so, this study is the first to link how people think about minds and bodies to self-injury behavior. The findings could one day help doctors and therapists better understand and treat NSSI. If strengthening the mental boundary between mind and body helps people recognize their emotions more clearly, it might also help reduce the urge to self-injure.