The first mass killer of the 20th century, serial killer Albert Camus, is believed to have killed around 50 people.
But scientists believe it may be possible to turn us into such killers.
Their new research looks at the brainwave activity of people who have sex with strangers, and their behaviour during and after.
And, as part of their work, they asked participants to imagine being a stranger.
In their experiments, they recorded their brainwave patterns while they watched someone else perform a task.
They then looked at the participants’ brainwaves and tried to match them to their own brainwave pattern.
The brainwave recorded by the stranger The participants were then asked to imagine having sex with someone else, a person of the same gender, and with a stranger of the opposite gender.
They were then shown a photo of the stranger, and were asked to indicate how they would feel about that person.
In a previous study, they found that if you’re attracted to people of the person of your choice, it would make you feel less anxious and less sexually aroused than if you were attracted to someone of the other sex.
The brainwaves of the people who were in a relationship When the participants had sex with a different person of a different gender, their brainwaves went up in a way that indicated they felt more aroused and anxious.
The researchers said they were able to see how these patterns would change as the participants got older.
“We were able … to get a better idea of what the brains of those who have engaged in a long-term, sustained relationship with a new partner would look like,” said Dr Simon Sussman, the lead researcher from the University of Sussex and the university’s School of Psychology.
The team also found that the brainwaves recorded by a stranger made it easier for the researchers to identify the individual who had just committed the crime.
“We were seeing that the individual with whom you were engaging had changed, in the way they thought about their partner, in their behaviour, in how they felt,” he said.
Dr Sussmann said he hopes the results will help people with long-standing romantic relationships understand their partners better.
“People with long, established relationships are more likely to be in an open relationship than someone who hasn’t had a long relationship,” he explained.
“But the idea is, we’re not going to have a long, open relationship with someone who’s in a bad relationship, who has a lot of problems, and is just looking for a way out of it.”
But the study also has implications for people who think they’re attracted only to a certain gender.
“Our study was really about how people with different gender identities would react in a romantic relationship with another person of that same gender,” he added.
“And we really didn’t know whether the brain activity of that person would also change, but we were pretty confident that it would.”
We would love to do a study in the future looking at whether this can help people in a similar situation in a different way, and to see whether it can help in a longer-term relationship as well.