.
IMO..by knowing their character traits. All the aspects of the person's behavior and attitudes that make up that person's personality, both good and bad.
Can you always tell if a person is lying to you Beans? Some folks are so good at it. I'm not that good a lie-detector. So if you are then that's great. I tend to believe people when I probably shouldn't but I don't know how else to be! Of course I don't believe a dam* thing any politicians say

but that's another subject. Thank you for your reply m'dear! :)
Hello Rosie:
We don't have a test like that, and we never will.. It's a good thing too.. Certainly, people who test negatively would be put away just because of what they think.
excon
PS> (edited) It occurs to me that Scientology's "e" meter test is an attempt to measure character, isn't it???
I don't know anything about Scientology except that it is a cult to stay away from at all costs. I mean c'mon. Tom Cruse and John Travolta are its prime stars. Need I say more? Thank you for your reply excon. I'm not sure what you mean exactly though. Put away for what they think? I'm talking about something that would test honesty/integrity/kindness/ truth/caring /modesty/empathy . Why would anyone be put away for being any or all of those things? Please e
xplain! :)
Hello again, Rosie:
Nobody would be put away for BEING those things.. They'd be put away for NOT being those things.
excon
Trust, but verify is a form of advice given which recommends that while a source of information might be considered reliable, one should perform additional research to verify that such information is accurate, or trustworthy.- wiki I'll add 'within reason' to that.
Look at their past character traits. Trump, a newbie to politics, was a liar well before entering same. Happy Sunday Rosie.
We don't know what intelligence is. The people who sell the test are unable to explain what it measures. Character in most cases only means undetected crime.
Thank you for your reply excon. :)

Very true m'dear. His supporters must be liars too. Truthtellers find him despicable, reprehensible and evil. :) Thank you for 

your reply Beans!