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Sleeping woman (symbolic image): Dreams often prepare for waking life

Photo: Dmitriy Bilous / Tetra images / Getty Images

Why do we dream? What is the function of dreaming? So far, there are no clear answers to these questions, but at least there are explanations. According to some theories, for example, dreams make analogies to the real world and prepare dreamers for corresponding situations in everyday life.

In a study published in the journal Scientific Reports, a team of researchers compared the dreams of members of indigenous societies with those from Western countries. It turned out that culture and origin influence the nocturnal experiences.

For two months each in 2016 and 2017, researchers from the University of Toronto collected dream reports from members of two African groups: the Bayaka in the Republic of Congo and the Hadza in Tanzania – both communities that, according to the researchers, resemble traditional hunter-gatherers.

On the other hand, the authors drew on dream diaries of participants from Switzerland, Belgium and Canada, which came from studies that had already been published since 2014. In total, almost 100 dreams of more than 230 people came together in this way.

Attacked and rescued by the buffalo

"We found that the dreams of the Bayaka and Hadza are very dynamic: often they begin with a life-threatening dangerous situation, but end with a means of coping with this threat," says Lampros Perogamvros, a psychiatrist at the University of Geneva involved, in a statement accompanying the study.

When indigenous people were faced with threatening situations in their dreams, they often told how someone came to their aid. For example, an indigenous man recounted a dream in which he was attacked by a buffalo on open land but rescued by a member of his community.

"In the Bayaka and Hadza, the social ties are necessarily very strong," says David Samson, professor of evolutionary anthropology at the University of Toronto and first author of the study. This is because their communities are more focused on equality, both in everyday life and in the division of labor. "The social bond and trust in the community seem to ensure that the best way for them to emotionally process the threats in their dreams is through social relationships."

According to the authors, European and North American societies are comparatively more individualistic. There, people have comparatively less contact with large communities. Feelings such as ostracism, exclusion, shame also have to do with this individualism – which is reflected in the dreams.

For example, a Canadian person reported a dream in which she was ostracized at school by two friends during a group work. A feeling of fear that is more likely to occur as a threat scenario among Western dreamers. In such societies, bad dreams often simulate their fears and thus help to face them.