Beveridge on conditioned thinking
Psychologists have observed that once we have made an error, as for example in adding up a column of figures, we have a tendency to repeat it again and again. This phenomenon is known as the persistent error. The same thing happens when we ponder over a problem; each time our thoughts take a certain course, the more likely is that course to be followed the next time. Associations form between the ideas in the chain of thoughts and become firmer each time they are used, until finally the connections are so well established that the chain is very difficult to break. Thinking becomes conditioned just as conditioned reflexes are formed. We may have enough data to arrive at a solution to the problem, but, once we have adopted an unprofitable line of thought, the oftener we pursue it, the harder it is for us to adopt the profitable line.