Somehow we obtain some raw data, use a bit of memory, a bit of logic and enigmatically come up with a decision. Most of the time we fail to notice how enigmatic this process is and how little we control it.
For the first thing, we have two modes of thinking: intuition and deliberation, which do not always interact flawlessly. In too many cases intuition takes control where it shouldn't, which leads to systematic errors that often go unnoticed.
With knowledge of the internal human decision-making it is possible to not only persuade the minds of the jury, judge or arbitrator but to win their hearts as well.
According to research, even in judicial/arbitral decision-making the role of emotions is at least as big as that of reason.