[igfbyefc] Trust is measurable and predictable

Can person A trust person B with X?  Ultimately, this is a question whose answer can be measured (though the cost of betrayal may be not worth the benefit of trying to measure it).  As such, it is science: it can also be predicted, and the predictions tested and falsified.

All these features hold regardless of the definition of trust, which is interesting, because there are many definitions and special cases of trust.

Trust is, of course, very important to the functioning of society, so knowing who to trust, when, is one of the most important pursuits of knowledge.

But there's a problem.  We seem to have social mechanisms to hide the betrayals of trust.  People are always looking not just to backstab people they don't like, but to do so without acquiring a reputation of a backstabber.  What is going on?  Whatever it is, it is quietly harmful to society.