If you judge a person to be cold, for example, your behaviour towards her will be different than if you judged her to be warm. This much is obvious.
But did you know that your behaviour will still be affected if you have been told by someone that she is cold? Even if you are known to keep an open mind.
Not only that, you will also perceive the person to be such, no matter how you interact.
In an experiment, a new professor was introduced to a class and the students were given a fact sheet about the professor. Half the students read the fact sheet that indicated that the professor was 'cold' and the other half read the fact sheet that stated that the professor was 'warm'. In fact, these were the only words which were different in the fact sheet. The rest of the fact sheet was identical.
After the lecture, the students were asked to rate the professor. And guess what? It is as if the students were rating two different persons.
But that is not all.
In another experiment, it was proved that the army recruits actually performed as categorized. So those who were judged and categorized to be leaders actually behaved as leaders. The funny thing about the whole experiment was that the categorized was done randomly and only their commanders were told about it. It was the behavior of the commanders that was subtly passed on to the recruits who then behaved accordingly, irrespective of their inherent potential.
So, when two humans interact, their minds too interact. And the mind can play amazing tricks on us.
I think the mind has evolved faster. The rest of the brain is yet to catch up.
Remember this when you interact with people, particularly when you are in the position of strength. If you are the boss and you have decided that a subordinate is good for nothing, perhaps he is behaving that way because you think of him has good for nothing.