How do you assess the trustworthiness of a contact?

Background My startup is relying heavily on contacts, which I trust. If I improved my way of assessing whether a new contact is trustworthy or not, I believe my startup would be more successful. Sometimes I have for example dumped potential customers, by setting the price so high that it was unrealistic, just because I have a bad feeling about them. I could not even quite justify the reasons for my bad feeling myself, and much less explain them to others.

Question Are there any tricks I could use to assess the trustworthiness, which I could use in addition to my gut feeling?

The tricks I already use are things like checking the background and using my network to try to get information about the persons history. I also use Google, what I am after is more how to do this in one-to-one interaction.

I would also be interested in any practical guides on this, I know a lot of the theory being trust.

From my experience, there is no real way to know if someone is trustworthy, until they screw you. What I usually do is just look them up on Google, etc. Do my homework, and ask them questions about themselfs I already know the answers to. If you catch them in a lie or even a gross exaggeration, you might have trust issues in the future.

In one-to-one interactions I have one key thing I use which is to look for inconsistencies.

For example:

• Does their body language match what they are saying? If they are saying, "We always pay our bills on time, closed body language such as arms folded and leaning back in the seat would be contradictory.
• Do they say different things at different times? (Love Elad's technique of asking about things you already know the answer to.)

I have also found that if my gut is telling me to be cautious, if I think about it logically I can usually articulate solid reasons why I am feeling that way.

Be sure you are doing some back-channel references - folks your contact did not give you as a reference. You can find such people via LinkedIn, FB, etc. Your goal is to have a candid conversation with someone whom your contact has not "anointed" as a reference.

Formal references seldom give you valuable insights, for obvious reasons. Back-channel references are much more likely to be candid with you.