It is an art of determining physchopaths. Physchopaths are well defined by Laura Knight Jadczyk
http://laura-knight-jadczyk.com/tag/psychopathy/
and check out her book on psychopaths.
The main idea is that it is hard to tell apart a psychopath from a good human by behavior. Psychopaths are exceptionally good in deception and reveal their negativity only in actions, often under pressure, and most often for personal gain. Each human has negativity inside, but it is a question of integrity and inner strength of character to tell a good altruistic human from a psychopath. I really hope that you can tell the difference by looking at the soul.
Best movie on psychopaths is "Glengarry Glen Ross". Check it out. You will see the deception at its best.
You are very likely very good in figuring out which people are more compatible to each other based on astrological profiles. Likely, even without the use of astrology, you could tell which people will be great in working together. Humans use astrology to tell compatibility. For example Beatles with their manager were extremely stable and vibrant. When their manager died, they fell apart. I did their very primitive astrological analysis and found some interesting pattern which possibly was helping their compatibility. You want to make sure to combine people in a way which would be most productive.