In a newly born baby, the lungs are not yet functioning. When communication with the mother’s body is interrupted, carbon dioxide begins to accumulate in the blood of the newborn. It humorally acts on the respiratory center of the medulla oblongata and causes an instinctive breath. The baby begins to breathe on its own. The first cry of the child speaks of the beginning of breathing. Such a chain of congenital reflexes was manifested: birth – CO2 – inhalation – cry. In animals that give birth to cubs in water, this chain is somewhat different: birth – leaving under water – CO2 accumulation – ascent to the surface of a reservoir – inhalation. If such an animal, such as a newborn hippopotamus, is not allowed to emerge, it will die, since the inhalation can only follow after the ascent, otherwise it will inhale water. In humans and animals, there are not only incentive, but inhibitory unconditioned reflexes and instincts. The former are called positive, because they cause active actions, the latter – negative, since they cease to act. It is enough to recall how we freeze from a sharp sound, an unexpected touch. Negative reflexes in chickens are most conspicuous. When the chickens begin to hatch from the egg, the brood hen claws. By this, it causes a positive unconditioned reflex, induces chickens to activity. But a cat appears nearby, the chicken makes a short sound, and the chickens freeze: a negative, inhibitory reflex appears. The chicks in the egg did not see either the chicken or the cat, but they obey the signals of the chicken, which stimulate or terminate the action of the chickens.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.