Napoleon Hill’s teachings for reading human animal

The best place to study the man-animal is in your own mind, by taking as accurate an inventory as possible of YOURSELF. When you know yourself thoroughly (if you ever do) you will also know much about others.

To know others, not as they seem to be, but as they really are, study them through:

1-The posture of the body, and the way they walk.
2-The tone of the voice, its quality, pitch, volume.
3-The eyes, whether shifty or direct.
4-The use of words, their trend, nature and quality. Through these open windows you may literally "walk right into a man's soul" and take a look at the REAL MAN!

Going a step further, if you would know men study them:

When angry
When in love
When money is involved
When eating (alone, and unobserved, as they be- lieve)
When writing
When in trouble
When joyful and triumphant
When downcast and defeated
When facing catastrophe of a hazardous nature
When trying to make a "good impression" on others
When informed of another's misfortune
When informed of another's good fortune
When losing in any sort of a game of sport
When winning at sport
When alone, in a meditative mood.

Before you can know any man, as he really is, you must observe him in all the foregoing moods, and perhaps more, which is practically the equivalent of saying that you have no right to judge others at sight. Appearances count, there can be no doubt of that, but appearances are often deceiving.