Unconditional Human Reflexes: Classification and Phylogenetic Characteristics

Unconditioned reflexes mean a set of behavioral characteristics of a person with whom he is born. They do not require development and training and vary slightly with age, being dominant in everything that a particular individual does or behaves. In this case, a complex set of unconditioned reflexes is called instinct - a form of human vital activity that ensures the preservation of the species, the realization of self-preservation and eating behavior.

The classification of unconditioned reflexes divides them into specific species, grouped together. Among them are simple tendon and visceral reflexes. The complex includes defensive, food, sexual. Therefore, the concept of "unconditional" includes sexual, food behavior and self-preservation, as well as a grasping reflex, respiratory arrest, reflexes of the propriosensitivity system, and also cough. Among the simple ones, there are a lot of reflexes realized due to the segmental apparatus of the spinal cord, the significance of which relates to vegetative reactions and unconscious behavior.

The birth of a child is accompanied by a number of whole concrete conditions, thanks to which the birth and stay in the period of newborns are partially protected from external conditions under the condition of having a mother, as this provides close contact with it. The most notable unconditioned reflexes are search, food, and grasping reflexes. During life, they, in addition to food, are somewhat extinguished, and they are replaced by conditional ones, that is, those that require an incentive for their development. For example, if you put the baby immediately after birth on the mother's abdomen, he instinctively begins to look for the nipple, although at this time he is not hungry, and feeding is not a priority for both the mother and the baby. In this case, this method is used in obstetrics to establish the mother-child relationship, which later promotes feeding and lactation. Also, the child tries to catch the smell of the mother, after which almost none of the other women can feed him.

Another remarkable reflex, with which a person is born, is the ability to hold one's breath independently at the moment of contact of the head with water. In the womb the fetus is constantly surrounded by fluid, and independent breathing due to the development of the lungs in the most recent trimester is impossible. In addition, the child does not experience hypoxic and hypercapnic stimuli, and in the alveoli there is no surfactant, which reveals them. Therefore, in the aquatic environment, these unconditioned reflexes, despite their presence, do not appear, and after birth, babies are able to hold their breath while swimming.

Despite the fact that sexual instinct and self-preservation are congenital reflexes of a person, their manifestation is impossible at an early age. Here the situation is exactly the opposite of food behavior, because in the period from 1 to 4, although this interval is strictly individual, the instinct of self-preservation gives way to the desire to explore the surrounding situation, and the sexual reflex does not develop, since there is no data in the CNS about the opposite field.

The grasping unconditioned reflexes of a person are manifested even in the fetus, as evidenced by its presence in experiments in premature babies, which appeared due to caesarean section. This reflex behavioral reaction is probably a phylogenetic trail, a remnant from previous species of organisms. It manifests itself in the form of bending fingers and compressing the irritating palmar surface of the object. In conditions when a person did not live in a civilized world, these unconditioned reflexes helped to fix the child to the neck of the mother and hold on to her hands. The force of brush compression even at the moment of newborn is enough to sustain your own weight: putting your finger in the palm of your child you can simply pick it up.