Here’s an interesting quote by William Walker Atkinson:
“Every person is constantly surrounded with a thought‑aura which affects those with whom he comes in contact. Some people attract us without a word being spoken, while others repel us as soon as we come within the radius of their aura.
The aura of a man is composed of the essence of his prevailing thoughts—it reflects his general mental attitude. This aura is felt not only by man, but also by the lower animals. Children are very susceptible to its influences, and many unaccountable likes and dislikes of children are explainable in no other way.
Some persons are very sensitive to the thought atmosphere of others, and will sense at once the mental attitude of those with whom they come in contact. Some psychics are able to perceive this aura, and state that it varies in density and shade according to the prevailing quality of thought of the individual.
When one realizes the wonderful workings of the law of thought‑attraction he sees the importance of so controlling his thoughts that he may attract only the best and most helpful thought of the world, instead of the depressing, hurtful, negative thought which is being sent out from so many minds.
A man who maintains a hopeful, confident, fearless mental attitude will attract to himself like thought from others, and will be strengthened and helped by the influx of the outside thought, and will go on from success to success, aided by the combined force of the thoughts which he has attracted to him. He becomes as a magnet drawing to himself that which strengthens and aids him. Equally true is the fact that the man who maintains a negative, fearful, despondent mental attitude will attract to himself like thoughts from the great field of thought, which will pull and drag him down still deeper into the Slough of Despond. Remember, always, “like attracts like” in the thought world. And you may rest assured that whatsoever you think will attract a corresponding thought which has been sent out from the minds of others.
Have you ever noticed the attractive power of thought in the cases of strangers brought into contact with each other? Each draws to himself his kind. Place a hundred strange men or women in a room, and inside of an hour they have formed themselves into groups, each group representing a different type — a different mental attitude. Each instinctively attracts and is attracted by corresponding qualities in another.”