From your earliest childhood to this moment you have been forming first-hand opinions of other people by observing and interpreting their words, tones, and movements.  Sizing up men is not a new process to you.  But in order to be a certainly successful salesman of yourself you should observe more intelligently and discriminatively hereafter.  Instead of making up your mind about people without knowing just how or why you arrive at your judgments, classify your intuitions scientifically.  Know the reasons for your opinions.  You can be sure about the conclusions you reach as a result of your specific, exact observation of details.  The study and analysis of words, tones, and acts, coupled with a little painstaking practice, will make you an expert judge of other men.

[Sidenote:  Study Character Unobserved]

Do not seem to make an effort to observe the person you are sizing up, for that would impress him disagreeably.  Without indicating that you are watching him, mentally note and interpret his muscle structure, his manner of speaking, his gestures, the rate of his physical activity, the way his actions respond to his ideas, the type and tensity of his movements. Each item you analyze and translate should indicate to you clearly some fact about the inner man.

Of course you will not be able to read your prospect thoroughly in the first few moments after you meet him.  It is possible to make only a partial size-up then.  No one would reveal all his characteristics in such a brief time. But each indication you perceive and interpret correctly will aid you to attribute to him certain other, related traits. For instance, if the actions of a man indicate the characteristic of evasion, you may judge safely that he lacks courage, the highest sense of honor, some of the elements of perfect squareness and trustworthiness.  If he has a habit of under-estimating or “knocking,” and manifests this characteristic in something he says or does, you may feel certain he is not an idealist.  He is likely to be pretty “practical” in his views, and cannot be won by appeals to rosy visions.

[Sidenote:  Elements of Character are Consistent]

Analysis of a man’s true character usually shows that its elements are thoroughly consistent.  A human being is not a bundle of contradictions, but an aggregation of likenesses.  Every man differs from every other man; yet, generally speaking, one element of his character is not apt to differ radically from another detail of himself.  There are exceptions, but in most cases the seeming contradictions in an individual are only apparent opposites.  Supposed inconsistencies cause surprise because the true fundamental traits of the person observed are not discerned.  The outer man often seems to contradict himself.  But nearly always the inner man is consistent in his various characteristics.  This is the reason why your size-up should be restricted to discriminative observation of indications of the ego.