Answer:
Though I don't really get the question... this is my answer.
People can find truth through their family and friends by many reasons. One simple lie dectector is when the person's hand sweat, they get nervous, they constatly swallow, or they don't look you in the eye. Another trick that doesn't really work ,but superstitious people belive it works, is when a person lies they look to the left. When someone is telling the truth they are able to stay confident with the truth and look at you. They can speak the same story whereas liars sometimes forget the story they told you.
I hope this helps, Good luck with the assignment!