

Ask HN: How do you detect liars? - diminium

How do you guys detect liars in spaces outside of your domain space?<p>Right now, I have a pretty good in depth knowledge of a particular technological domain.  I've talked to various people about this domain and the words that come out of their mouth surprise me more often than not.  Basically, they are lying by either vastly overstating what this particular technology can do or saying things it can do when it can't.  They also say this with an air of confidence like they are positively sure of their lie.<p>It's very rare but when I finally meet someone who says the magical words "I don't know." I'm excited because I can finally talk to someone who actually knows their limitations of their technical knowledge!  Now I can at least have a discussion of what they know.<p>One day though I'm going to need to hire people in areas OUTSIDE my expertise.  I wouldn't have the deep technological knowledge to know if they have a clue on what they are doing.<p>Filtering out people who say "I don't know" would help but what other methods do you guys use to find the truth tellers from the liars?
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auganov
Well there's liars on both ends. On the one end you've got the fancy vocab
know-it-all smooth talker. On the other end we've got the I can learn quantum
finance on-the-fly guy (perhaps quantum finance is not too hard, but you get
the point).

Honestly though - I don't think anybody will give you a very useful tip as
most honest people will probably admit that their "gut" is still a very
important factor. But I do understand you're simply looking for inspiration so
not that it's pointless to ask.

Personally I think that most poor and average-level liars tend to play it
safe. They talk a lot, but most of what they say is stuff that's very
agreeable, they don't have the balls to make up their own complex-sounding
insight. Of course a top class liar will pass that. And sometimes, you know, a
liar is so top-class that he might even actually be able to do the job :-)

It's a game. And by setting it rules you're simply determining who's capable
of beating it. Someone will always be able to. I'd rather focus on making it
easy to fire them.

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eggbrain
The problem is sometimes people believe lies they've been told -- they might
have read an article somewhere that x can do y, when they really
misinterpreted the entire thing, and hold that (mis)belief in their head. They
might even sound confident when they talk as well, because to them it is true.

That being said, if someone has knowledge in the expertise you are looking
for, they should be able to break things down. So if you ask them a question
about Z, and they say "well of course I can do Z", you ask them to break down
what the steps they would go through in order to do Z. If they know their
stuff, it should be trivial.

On a side note, the people who know their limitations are, like you said, the
ones you want to talk to. Socrates was considered the wisest man in Greece, it
was said, because "[he] knew that [he] knew nothing"(paraphrased)

------
Someone
Not everybody who makes incorrect statements is a liar. People may not know
better or may skip details ("all birds can fly", "three times three is ten"),
either because they have learnt to be not too nerdy to people they do not
know, or because they know leaving out details sells better. I meet many more
of either of those than outright liars. So, the primary rule could be: in
general, people do not lie.

Also, you should never rule out that your 'pretty good in depth knowledge' is
not broad enough and/or not pretty good enough, relative to some people you
meet.

~~~
billswift
There are three possible reasons for incorrect statements:

1) Stupid but honest - doesn't know the truth and doesn't realize he is wrong.

2) Ignorant and dishonest - realizes he doesn't know and tries to cover it up.

3) Liar - knows the truth but lies anyway.

~~~
Someone
4) simplification - if a weatherman says "it will rain tomorrow" (s)he will
leave out lots of 'given', 'statistically', etc. Similarly, one can find fault
in any categorical statement ("1+1 equals 2" -> not in Z/2Z). If you meet a
person for the first time, establishing conventions for the level of
simplification can be difficult. That may lead one to think somebody does not
know what he is talking about.

There also are variations on #3 that I would not really call lying:

5) "Santa flies from the North Pole". Technically #3 above, but feels
different to me.

6) Politeness - as when answering a "do I look fat…" question.

~~~
spicyj
Actually, 1 + 1 is 2 in Z/2Z because 0 = 2, no?

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kaens
This is incredibly tough. I've found that if they can't go at least _a bit_
more in depth about whatever it is, or if they can't point to relevant
examples of whatever they're talking about, that can be an indicator of them
being full of it -- however, this isn't enough to make me suspicious unless it
happens fairly often, and if it was from an area I had absolutely zero domain
knowledge of it would probably be fairly easy to fake as well, if a bit more
rare for people to do so.

Other than having people that you _know_ are competent in X, or studying up on
X to the point where you can start to smell bullshit, I'm not aware of any
sort of really reliable techniques.

People who lie a lot tend to suss themselves out over time, but that doesn't
mean they haven't cost everyone a lot of time and money by the time they do.

Maybe some of the body language indicators could serve as an additional "hmm
seems like this person might be full of it" -- blinking more, looking up and
away, etc. These are _also_ not reliable as a steadfast rule though,
especially in fields that are filled with introverted left-brainers, ha.

It'll be interesting to see if anyone has any decent techniques for this.

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veyron
Haha have to cite a study here [Kruger and Dunning 1999, Unskilled and unaware
of it ...]

(recollection from CFA Level 3 material)

So the authors of the study asked people to rate how they have performed on a
logical reasoning test. What they found is that people in the lower half of
the test results scored less than 40% correct, yet they thought that their
scored in the 60% range. This was particularly bad for the lowest 25% who got
10% correct.

The irony is that people who did very well (top quartile) actually thought
they performed worse (55% vs 85% performance)

tl;dr: the skills needed to correctly answer questions are exactly the skills
needed to evaluate performance. The best bet is to have some sort of objective
measure. Learn a little bit about the field you are interested in evaluating
others in. Think about fizz-buzz: a non-programmer can ask the question and
get people to sweat

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buckwild
Saying "I don't know" seems like a display of honesty to me... I'd rather have
someone reply with "I don't know" than give me a load of bull...

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bks
So I went to a course from <http://www.humintell.com/> in San Diego a few
weeks ago. Now I realize that this is not specifically what you were asking,
it is a way to work on your people reading skills. You said you were going to
be hiring people, and if you interview face to face - this type of expertise
could be helpful.

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Mz
I learned to "trust my eyes, not my ears" so to speak -- ie what people
actually do in preference to what they claim about themselves. If there is a
big disparity between the two, they are untrustworthy, even if they aren't
intentionally deceiving you. I find it useful to remember that people who are
lying to themselves about something cannot tell me the actual truth, not
because they are intentionally deceiving me but because stating the truth to
me would make it impossible to keep lying to themselves. I also look for
patterns rather than specific instances. I mean, if someone makes a miss-
statement, he may not be lying. He may be tired, distracted, mis-informed,
etc. So I don't read too much into a single incident. I am big on giving
people the benefit of the doubt. I used to think I am "forgiving", but I have
concluded that is not entirely accurate. It is more accurate to say I am slow
to judge, but once I have arrived at a definitely negative view of someone, I
am a very hard sell.

I concluded years ago that "Forgiveness is a gift. Trust is earned." Abusive,
untrustworthy people are very, very big on claiming you should "forgive and
forget" and not hold some transgression against them. Such people should not
be trusted any farther than you can pick them up and throw them. Decent human
beings who made an honest mistake typically are fine with making it right and
don't expect you to simply give them a pass. Some folks are simply young and
have not yet made a definitive choice as to which camp they belong to. I
generally give such individuals a chance to prove themselves if I can, even
sometimes in the face of behavior I wouldn't likely tolerate from someone
older.

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veyron
What exactly is the technological domain? I'm sure someone on HN knows enough
about it to give you some good starting points for asking questions

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dpio
I play L.A. Noire to hone my lie detecting skills.

