Intuitively, it seems to us that killers are secretive, suspicious people whose asociality can be seen a mile away. However, in fact, most of the killers are those who, until the moment of the crime, seemed completely normal to everyone. Evolutionary psychologist David M. Bass conducted a shocking study: for 7 years, his team interviewed 5,000 absolutely ordinary law-abiding people from different countries and cultures. They analyzed more than 400,000 murders already committed and concluded that every person is able to cross the line.