The one thing I can trust about anyone is that they frequently lie. You could not have society without lying. This can be fabrication and embellishment of stories we tell - all the way to cover ups of misdeeds.
I would love to see how many people would consent to a lie detector test for our simple lies:
Do you wash your hands after going to the bathroom.
Do you pick your nose on occasion and "put it somewhere".
Do you ever double dip?
Do you drink out of the family juice bottle instead of pouring a glass?
Do you look in people's medicine cabinet?
If you are a guest in someone's house and they aren't home do you take a "personal" tour?
Some scientists think our big brains developed specifically to conceal information from our social groups.