The 12 primitive reflexes of babies

Throughout our development as a species, humans have inherited from our non-human ancestors reflexes, behaviors that depend on the central nervous system and occur in response to certain types of stimulation. A special case is that of primitive reflexes, which appear in babies but they are lost after a few months of life.

In this article we will see what these reflexes of ancestral origin are and how they are expressed during the first weeks after birth.

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The primitive reflexes of babies: types and characteristics

The reflections are activation patterns of movements that are triggered by certain stimuli and that occur automatically and beyond our consciousness, and always in the same way, and that they are caused by nerve cells that are not part of the brain. They usually have as their origin an adaptation to the environment, since the nerve cells that start them form a network of interconnections that does not pass through the brain, so that between the uptake of the stimulus and the appearance of the reaction, very little time passes, which in certain situations helps us avoid dangers.

However, sometimes these reflexes become useless as an animal lineage evolves and moves further and further away from the type of behaviors and ecological niche that have been useful to you in the past. Here's what happens to some of the primitive reflexes of babies: they are "remnants" of adaptive mechanisms that were useful millions of years ago, but since they are no longer so, they give way to another type of functioning of the nervous system, so their existence in the members of our species only lasts a few weeks. In other cases, they are mechanisms that are only useful when we are babies, and that can occur unnecessarily that the child is able to plan patterns of action or to be clear about the objectives to get.

Below we will describe 12 of the most characteristic primitive reflexes of early childhood. Unlike the blink, refraction, or patellar reflex, primitive reflexes are not maintained during adulthood; its origin is associated with an increase in the survival of babies under the conditions in which our species evolved.

The absence of these reflexes is a sign of neurological problems., although sometimes it can also be due to conditions of stress or psychological discomfort. On the contrary, the presence of primitive reflexes in stages of development in which they should not remain also indicates some type of alteration of the brain.

1. Grip

Before reaching about half a year of life, babies are able to grasp objects with force with their fingers if they press the palm of one of their hands. At an adaptive level, it allows children to suspend their own weight for a short period of time. The origin of this reflection has to do, probably, with the times in which the offspring clung to the fur of their mothers or fathers.

2. Search or rooting

The searching or rooting reflex is associated with breastfeeding: when babies younger than 4 months notice that something touches their cheek or mouth, turn their heads towards the object and open their mouths to suck on it. This reflex is also detected in some adults with severe cerebral palsy.

3. Suction

The sucking reflex works in a complementary way with the seeking reflex. When babies feel something touch their palate, they instinctively tighten it with their tongues; the function of this reflex is to promote the secretion of milk by the mother's nipple.

4. Crawling

This behavior appears when the baby's belly is supported on a surface and the foot is held; the little one begins to move all four limbs in a coordinated way to move across the floor. At 4 months this reflex is no longer present.

5. Automatic running

As the name suggests, this reflection allows babies to step rhythmically when held in an upright position with bare feet on a flat surface. It disappears between 2 and 3 months of life as a consequence of changes in the relative weight of the legs.

6. Swimming

If a baby is held with its belly against the water, for example in a bathtub or on the beach, it begins to move their arms and legs and to breathe out through their mouths, although they may swallow a lot of water in the process. The swimming reflex disappears at 6 months of life.

7. Moro or startled

The Moro reflex, startle or hug is produced when babies younger than 5 months hear a sudden loud noise. Stimulation of this type causes them to first extend their arms and legs and then close their arms against their own body. This reflex would help babies to stay attached to their mothers while they are being transported.

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8. Babinski's

When the side of a baby's foot is struck, the baby extends the big toe backward and spreads the other toes while twisting the foot inward. The absence of this reflex on many occasions indicates insufficient myelination of the motor pathways of the brainstem.

9. Magnus or tonic-cervical

The asymmetric tonic neck reflex causes babies to turn their heads to the side and adopt a protective posture when lying on their backs. It is a behavior that precedes eye-hand coordination. Sometimes it is also called "fencer's reflex" or "fencing position".

10. From Landau

This reflex, which disappears at 3 or 4 months, is triggered when the baby is suspended on his stomach and with his head flexed. First extend your head, trunk, and legs, and then flex the rest of your body. One of the primitive reflexes that involves more muscles.

11. Babkin's or palmarmental

Babkin's reflex is triggered by pressing both palms of the baby's hands while the baby is lying down backwards. When this happens the little one opens his mouth, closes his eyes and turns his head. It also stops appearing between 3 and 4 months of life.

12. From Galant

The infantile Galant reflex is present for the first 6 months after birth. It consists of turning the body, with a search or orientation function, when the baby notices that its back is being touched.

Bibliographic references:

• Fletcher, Mary Ann (1998). Physical Diagnosis in Neonatology. Philadelphia: Lippincott-Raven.
• Grzywniak, C. (2016). "Role of early-childhood reflexes in the psychomotor development of a child, and in learning". Acta Neuropsychologica. 14 (2): pp. 113 - 129.
• Pedroso, F.S.; Rotta, N.T. (2004). Babkin Reflex and Other Motor Responses to Appendicular Compression Stimulus of the Newborn. Journal of Child Neurology, 19 (8): pp. 592 - 596.