The Principles of Stupidity

1. We always underestimate the number of stupid people
2. The probability of a person being stupid is independent of any other characteristic of that person
3. A stupid person is someone who causes damage to another person, or a group of people, without any advantage accruing to himself (or herself) — or even with some resultant self-damage
4. Non-stupid people always underestimate the damaging power of stupid people. They constantly forget that at any moment, and in any circumstance, associating with stupid people invariably constitutes an expensive mistake.
5. A stupid person is the most dangerous person in existence
6. Stupid people don’t know they are stupid

The above has been floating around the net for a while. While it makes an interesting read I think that having a boolean criteria of labelling someone as stupid is not necessarily accurate. While there are a small number of people who are stupid, there are many more people who are good at some things and stupid when they act outside their area of expertise. There is a saying “never take investment advice from your dentist” which is apparently due to the incidence of con-artists targetting wealthy people (such as dentists) who sometimes then pass on the bad advice to their customers.

One stupid thing that I did a few years ago was to spend more effort in choosing a mobile phone than on choosing a car. I was totally happy with my mobile phone but not totally happy with my car – and the car cost a lot more… Of course the difference between pure stupidity and tactical stupidity (for want of a better term) is that a smart person who is about to do something stupid can generally be persuaded not to do it with a logical argument. If someone had pointed out to me the fact that the amount of time spent on background research for a decision should be in some way proportional to the amount of money involved (maybe proportional to the log of the value) then I would have been convinced.

So for rule 4 maybe it would be best to say taking advice from someone in an area where they are stupid is a mistake. For rules 5 and 6, if someone is known to be smart in other areas then tactical stupidity may be overlooked (until it’s too late).

Update: Don Marti commented with this link http://www.math.wisc.edu/~miller/old/incomp.txt about incompetent people being unable to judge their own level of incompetence as further evidence for point 6.