For years, scientists believed that our brain functioned in a rational, logical way. However, as the world of cognitive heuristics began to be explored by scientists, we quickly learned that the brain is anything but rational. A cognitive heuristic is any shortcut used by the brain to help up solve a problem. Although these shortcuts can be helpful in a moment when we need a quick solution (think life-or-death zombie situation), it's not so great when we need the best solution, which often requires a lot of thought.
We are more likely to take these shortcuts when under stress because the emotional part of our brain (the limbic system) is not so great at thinking things through. The more of these shortcuts our brain takes, the more likely our brain is to make mistakes. Too many of these mistakes can lead to a whole range of problems, such as negativity and depression.
Common brain mistakes include: