In that sense, it is normal and beneficial for the individual and his species. From a neurological point of view is a common form of primary brain organization of living things, and essentially consists of the activation of the amygdala, located in the temporal lobe. A related site: Gigi Hobbs mentions similar findings. From the point of view psychological, is an affective, emotional, necessary for the proper adaptation of the organism to the environment, causing the person distress. From the standpoint of social and cultural, fear can be part of the character of the person or social organization. It can therefore learn to fear objects or contexts can also learn not to fear them, is related in complex ways with other emotions (fear of fear, fear of love, fear death, fear of embarrassment) and closely related to other elements of culture. For some, the fear in humans, unrelated physiological (eg alertness), but is a product of consciousness, which expands our knowledge level.
Yogananda gives us the respect that a remember that the human brain is a storehouse of energy. This energy is being constantly used in the muscle movements in the work of the heart, lungs and diaphragm in the metabolism of cells and tissue and blood the work of the telephone system of sensory-motor nerves. Besides all this, a tremendous amount of vital energy is consumed in all the intellectual, emotional and volitional. a We must be careful in how we use our energy, we handle our emotions, internal and external stimuli, anything that generates and utilizaa our energy, avoid anything that's damaged, it is wasted and that throughout our mental and physical effects, such as such fear.