One can say that it is stress that leads to black and white thinking, because this simplified process allows an animal (including us) to make a quick decision when confronted with a stressor. What happens in our day to day lives is that many things trigger our stress response. Family, traffic, work, school, social media (now the number one trigger of stress). As a consequence, black and white thinking becomes the norm. We become accustomed to believing our assumptions, even creating elaborate stories to support them. These stories get reinforced by the media we choose to consume, and we then become totally imprisoned in this toxic mindset. Welcome to 2021!