People have long noted that individuals diagnosed as schizophrenic usually manifest disturbances of language, communication, and abstract thought. One way to examine that disturbance is to ask patients to interpret various common proverbs, as psychiatrists have done since before the turn of the century. (Interested readers can find a layperson-suitable discussion of this method's utility in the modern day at the following link: AAPL newsletter.)
Originally, patients' responses were evaluated by their correctness. Now they're graded on their degree of abstraction. Responses that understand the sayings literally or in simplistically concrete terms are generally considered to be signs of a failure to abstract, although illiterate or mentally challenged individuals also tend to respond that way, and individuals encountering a proverb for the first time are less likely to recognize its symbolic meaning. It seems clear that cultural exposure to proverbial forms, to the idiomatic usage of phrases and scenarios, affects how we recognize such methods of communication.
But why was the 'correctness' criterion dropped? Because perfectly normal people, whom no one would consider schizophrenic, often gave interpretations that wildly conflicted with what the interviewer considered to be the correct one. Which interpretations were 'correct' depended heavily on the traditions and cultures that the listeners came from.
Let's consider a classic example of a proverb often given divergent interpretations:
The rolling stone gathers no moss.
People from societies where stability and slowly-developed connections are valued consider this saying to be a warning of the dangers of activity and change. Without staying still, beautiful moss won't grow. People from societies where activity and change are valued, however, consider it to be a prescription for how to avoid decay and degeneration. If you don't keep moving, you'll be covered by moss!
When asked to explain their interpretation, the value of moss growth is typically presented as desirable or undesirable, depending on the defended meaning. But if you start out by asking people whether moss is something to seek or avoid, there's no clear preference outside of specific contexts. People generally don't have aesthetic preferences either way; overall, people don't care.
So the symbolic meaning of the mossy growth doesn't determine how people interpret the saying; people invest the moss with meaning to justify the judgment they had already reached. This is may be an example of what people at this site would call a 'cached thought'. Rather than giving a reason for their judgment, people reply with rationalizations that have nothing to do with why they reached their conclusion. Rather than thinking about why they decided as they did, people bring out a ready smokescreen.
What's the actual logical structure of the saying? Rational analysis sheds a great deal of light on the question. The meaning can be stated in various ways, all equivalent.
Stability is required for the development of certain states. Activity is incompatible with the development of certain states. (Desirable/undesirable) states can be (encouraged/prevented) by (engaging in/avoiding) (necessary precursors/incompatible conditions).
The saying encodes a pattern that expresses a relationship, but the pattern is devoid of evaluation. It's a blank screen upon which people project their pre-existing values and judgments. To truly understand the proverb, it's necessary to recognize which aspects of our perception are the saying itself, and which are our own ideas projected onto it.