From the psychological point of view, it is a State affective, emotional, necessary for the correct adaptation of the organism to the environment, causing anxiety in the person. From the social and cultural point of view, the fear can be part of the character of the person or social organization. You can therefore learn to feared objects or contexts, and can also learn not to fear them, is related in complex ways with other feelings (fear of fear, fear of love, fear of death, fear of ridicule) and has close relation with the different elements of culture. For some, the fear in humans, does not save any physiological relationship (such as alert reaction), but will be a product of consciousness, which expands our knowledge level. Yogananda gives us in this regard, to remember that the human brain is a store of energy. This energy is being constantly used in muscle movements, in the work of the heart, the lungs and the diaphragm, in the metabolism of the tissue and blood cells and in the work of the system telephone sensitivo-motor of the nerves. Besides all this, a tremendous amount of life energy is consumed in all intellectual, emotional and volitional processes. We must be tuned in as we use our energy, we handle our emotions, internal stimuli and external, everything that generates and uses our energy, to avoid all things that deteriorate it, is wasted and that along produces us psychic and physical effects such as for example the fear. Very interesting information, that the mechanism that triggers fear is found, both in people and in animals, in the brain, specifically in the limbic system that is responsible for regulating emotions, the struggle, the escape and avoidance of pain, and in general of all the functions of the individual and the species conservation. This system checks constantly (even during sleep) all the information that it receives through the senses, and makes it through the structure called the amygdala, which controls the basic emotions, such as fear and affection, and is responsible for locating the source of the danger.