Brain research in Rwanda: How do intergroup biases between former perpetrators and victims evolve after the genocide against Tutsi?

22 November 2022 |

Nearly 30 years ago, Rwanda went through a particularly brutal genocide perpetrated against Tutsis. The perpetrators were mainly regular citizens: colleagues, neighbours, family members… Today, both perpetrators and victims live side-by-side peacefully. But in a post-genocide society, can intergroup biases be ever reduced between individuals? Ghent University researcher Emilie Caspar was the first neuroscientist ever to conduct research with former perpetrators, victims and their children locally. And she saw that the genocide appears to have long-lasting marks on empathy between groups.

Header Emilie Caspar

“Humans are inclined to show less empathy towards people from other groups,” Professor Emilie Caspar starts to explain. “We call this the Intergroup Empathy Bias, and it’s a well-known phenomenon. A hypothesis to be tested against empirical data is that the Intergroup Empathy Bias is accentuated and last longer in a post-genocide context where former perpetrators and survivors continue to live in close proximity.”

In fact, they noticed in the study, the bias between both groups was still strong after all these years post-genocide. What is more: we saw that the reduced empathy for the other group transferred to the next generation, who had not experienced the genocide directly. The reduced empathy does not involve a lack of prosociality between groups. But it shows that intergroup biases can hardly evaporate in a post-genocidal context, which could have enhanced them.”

On the road in Rwanda with an EEG

To conduct her research, Emilie went to Rwanda. This is exceptional, especially for a neuroscientist. The bulk of her colleagues focus on the brain in the western world. Mostly, they do this for practical reasons: research in less developed countries requires certain adaptations.

Emilie, too, encountered the occasional roadblock. “I would have preferred to work with an MRI scanner because they’re able to visualise brain activity in great detail,” she says, by way of example. “But, in practice, this would have been impossible: in Rwanda, MRI scanners are only found in Kigali and may only be used in a medical context.”

But she wasn’t going to be stopped by this: out of necessity, she utilised a portable electroencephalogram (EEG) for her brain research. “Because how can we hope to fundamentally understand mankind if we only ever analyse brains in a western context? For my research, I couldn’t simply study the brains of Rwandans in Belgium. Simply said, it was necessary for me to go to Rwanda myself.”

An EEG measures electrical brain activity using electrodes placed along the scalp. “When experiencing empathy, our brain registers other people’s pain in the same way as it registers pain in our own body,” she explains. “This makes it easy to measure. Thankfully, studies show that a scalp EEG also delivers good results.”

Could less empathy be an explanation for atrocities?

Her brain scans showed that former perpetrators showed less empathy towards victims compared to their own group, and vice-versa. To their children as well. Is this a consequence of violence experienced during the genocide or is it a factor that contributed to widespread of violence? Can this be a possible explanation for why groups across many societies tend to repeatedly commit atrocities on each other over time,” says Emilie. “But such link should be confirmed in future research”.

The handy thing about a scalp EEG is that it’s very mobile. This was very important to Emilie since both former perpetrators- and victims of genocide didn’t all live in the capital. On the contrary. “We travelled to a different village every day. This brought us to some very rural locations,” Emilie explains. It didn’t make her research any easier: people there often lived in mud house and had no electricity, which she needed to conduct her research.

Winning the trust of the locals

“For this reason, we usually set up in churches or cafés,” she continues. “And then we still had to convince them that these kinds of brain scans were entirely harmless. They didn’t really trust the EEG. For example, they were scared that it could read their mind. Unlike people who live in urban areas, most of recruited participants lived in rural areas and had never even seen a keyboard up close in their entire lives, so they had very little knowledge of technology.”


To gain their trust, she got the help of Prison Fellowship Rwanda, a local organisation dedicated to helping ex-convicts rebuild their life. “The local population knew them and trusted them. They helped us recruit participants. Without them, it would never have worked.”

After Rwanda, Cambodia

In the meantime, her research in Rwanda hasn’t finished yet, on the contrary. Emilie: “I want to understand why some citizens followed or follow orders, even though it leads them to committing terrible acts, and other don’t. How much does the feeling of empathy influence this behaviour? In addition to this, there’s also the case of ‘les Justes’, the group of people who risked their lives by helping Tutsis and moderate Hutus go into hiding, in the same way resistance fighters did during the Second World War. What drives them?”

Choosing Rwanda as a focus for her research was no coincidence. “What is unique here, is that quite some time has passed since the genocide took place. In several countries across the world, intentional acts of destruction of people are still going on. Politically, this makes it a very sensitive subject and the governments there are not receptive to this kind of research at all. The government of Rwanda is receptive, reason why I conducted this research. Besides this, survivors are still alive and perpetrators and survivors live side-by-side. This isn’t the case for the Holocaust, for example.”

Afterwards, Emilie is going to Cambodia. A genocide took place there during the 1970s, about twenty years before the one in Rwanda. “That time difference is noteworthy: how much does the trauma from genocide still influence both groups today, after such a long time? And how do their descendants view each other?” In this way, she wants to keep studying intergroup biases and their consequences on the following generations.

Today, Emilie works closely with a number of different NGOs that help citizens recognise hatred, violence, and their consequences such as Radio La Benevolencija, Prison Fellowship Rwanda or Documentation Center Cambodia. Soon, she plans to start helping to develop educational programmes addressing intergroup biases and focusing on the prevention of large-scale violence following authoritarian orders – to help prevent future genocides.


Emilie Caspar was previously affiliated as a researcher with the ULB, University College London and the Dutch Institute for Neuroscientists. She’s the 100th ERC grantee at Ghent University. Three days after her appointment as professor at Ghent University, she commissioned a tattoo of a nervous system on her neck. It was something she had promised herself during her studies that she would do if she was ever tenured academically.

Read also

”There are countless ways to be a good family”

Broadening our view of the world is what Ann Buysse wants to achieve with her book 'Zoveel tussen ons’ (So much between us). She is a professor and dean of the Faculty of Psychology and Educational Sciences. "I have never been so unsure about anything before. Especially because it has not become a purely academic book. I also put a lot of myself into it."


How (un)healthy is worrying?

We all worry from time to time. It can even be good to clear the head, says professor Ernst Koster (department of Experimental Clinical and Health Psychology). However, it can also get out of hand.

Ernst Koster

Do you fall in love more quickly in the summer?

“Summer lovin', had me a blast. Summer lovin', happened so fast.” Danny and Sandy felt it already in the classic film Grease: during the summer there is love in the air. But is there any truth in it? Do we fall in love more quickly in the summer? 


Suicide prevention game nominated for Belgian Game Awards

April 2021 saw the launch of Silver – a serious game with the aim of helping young people learn about mental health. Now, just a few months later, the game has been nominated for the Belgian Game Awards. We reflect on the journey so far, and discuss the next steps with Eva De Jaegere, who helped develop and do research for Silver.