See How People Treat Strangers to Get Rid of the Troubles in Their Lives.
The problem with assholes is that they don’t always show up until you start working too closely with them to end the relationship. To avoid getting into trouble, watch how the people you meet treat strangers.
As Business Site Inc. notes, assholes are often nice to people they need something from, but they will start showing their true colors to strangers. Move forward in line, cut short with a waiter, or behave aggressively in traffic. How this person interacts with strangers can tell you a lot about how they will act when you start to interfere with them:
Observe the reaction to strangers: go to lunch and watch closely how the waiting waiter is treated, or how in the cafeteria, how the candidate walks through the line at checkout.
Of course, everyone can have a bad day, so it’s fair to watch it over a period of time. However, the way they relate to others needs to be given the meaning it deserves. If you cannot trust that your potential business partner will be polite or fair to a waiter in a restaurant, you probably cannot trust him to continue to treat you honestly.