Are we good or evil? And is violence something that can be elicited from any one of us? DW goes on a neurobiological search for the origins of human violence.
On a near-daily basis, the news cycle is filled with stories of terror - car bombs, gun attacks, suicide bombings, decapitations. The perpetrators are then painted as "sick" men - they're usually men - who have nothing in common with "normal" people.
Or do they? Is mankind inherently "good?"
Or somewhere, lurking inside each of us, is there a beast waiting to be unleashed, one capable of gruesome, awful acts?
In other words: Are the seeds of violence in all of us?
Psychotherapist Joachim Bauer is of the generation of scientists questioning and expanding upon Sigmund Freud's theory of "aggressive instinct."
Bauer, the author of "Pain barrier - on the origin of daily and global violence" ("Schmerzgrenze: Vom Ursprung alltäglicher und globaler Gewalt"), told DW that, "The question of whether it belongs to the primal nature of man to engage in violence is, of course, highly interesting to neurobiologists."
Scientists have therefore conducted experiments to show whether the brain's reward system kicks in when people - with no provocation - engage in violence. The result: For an average, healthy person, there is no "reward" for practicing violence.
"The relevant systems of the brain do not kick in," Bauer says. "What does allow those systems to kick in is when we succeed in achieving affection, recognition and appreciation."
If gaining appreciation through violence sounds paradoxical, it is scientifically provable: Our desire for recognition, for the positive chemical splash that results in the brain, does not necessarily encourage good interpersonal relationships. Quite the opposite.
"Humans are prepared to do evil to be appreciated, and for a sense of belonging," says the neuroscientist.
Thus can brain research perhaps explain what sociology and social psychology often describe - namely, that youths join violent organizations because they finally feel they're in good hands. And their brain's reward system also gets a hit.
It's a mechanism that Bauer believes leads hundreds of young men to leave Europe of their own free will and join in a "holy war" in Syria and Iraq.
"You could say, scornfully, 'They're losers.' But a society shouldn't produce losers since these people then run the risk of joining radical groups in which they find their own self-worth."
Exclusion as pain
The fact those who later become violent offenders often number among the losers of life is not a new discovery. Neglected by parents, failed by their schools, discriminated against by a majority in society. Descriptions of the perpetrators repeatedly describe a similar pattern, one picked up by the media as a means of explanation.
What's rarely talked about is what exclusion and discrimination actually do to the human brain. Neuroscientists have studied this in detail.
"With exclusion and humiliation, the same areas of the brain spring into action as during active pain - the so-called pain matrix," says Bauer. "That means, from the brain's perspective, pain is not merely a bodily attack, but also social exclusion and humiliation."
And brain research has shown that pain is the greatest driver of violence. This is likely determined by evolutionary adaption since we retain the ability to become aggressive to protect ourselves from danger. Evolution also justifies the fact that our brain equates exclusion with pain since our ancestors lived in social groups. Exclusion from the group was often equated with a death sentence.
"Because pain is the strongest stimulus for aggression, you can understand why people or population groups that are affected by exclusion are more willing to show aggression," says Bauer.