I'm just gonna quote what I said when this was on Metafilter a few months back:
"Anyway, yes, the fundamental problem in these questions is not how people think -- it's that the question they want the respondent to think they're asking, and the question they claim they're actually asking, are two different things.
The lawyer/engineer one is a classic example of this; what they hope is that you will read it as "how likely is it that these personality traits correlate to an engineer", so that they can then swoop in and say "what we were really asking is the mathematical definition of a percentage!"
Which ultimately tells us very little about the respondents and quite a bit about the people conducting the quiz..."
"Anyway, yes, the fundamental problem in these questions is not how people think -- it's that the question they want the respondent to think they're asking, and the question they claim they're actually asking, are two different things.
The lawyer/engineer one is a classic example of this; what they hope is that you will read it as "how likely is it that these personality traits correlate to an engineer", so that they can then swoop in and say "what we were really asking is the mathematical definition of a percentage!"
Which ultimately tells us very little about the respondents and quite a bit about the people conducting the quiz..."