What Foetuses Learn Before They Are Born

Nature vs. nurture, free will vs. determinism, little adults vs. blank slate…controversies that have led to debate throughout time and across disciplines.

What are the influences that create who we are and how we adapt to our environments?  Are these influences within our control?  At what points throughout our learning lifespan do environment and biology influence us most?

Annie Murphy Paul explorers these issues through the accumulation of research in her book “Origins: How the Nine Months Before Birth Shape the Rest of our Lives”. What becomes clear in this culmination of the scientific literature on prenatal influence is the idea that while in the womb, biology and environment become intertwined in such a way that the debate over nature versus nurture becomes moot.

Nature and nurture become indistinguishable in that the foetal environment is in essence a biological entity.

Before describing some of the more salient aspects of foetal research it is important to understand that the construct of learning discussed by Murphy Paul is significantly different from measurable intelligence later in life. Murphy Paul discusses learning in terms of influence and recognition.

Modern day foetal enrichment activities such as playing classical music to increase IQ may be supported by anecdotal insistence, but has not been evidenced through scientific methods.  Murphy Paul discusses learning on a much more visceral and sensory level.

What is this learning that takes place so early in life?  According to Murphy Paul, it is adaptive. This early learning serves as a means of incorporating critical information about the external environment into the biological makeup of the foetus impacting later behavior.

Sensory information relating to survival mechanisms are communicated to the developing baby through the mother.  Murphy Paul states that the mother acts as the “narrator” informing the foetus of the outside world.

Much of the information passes through the sensory inputs of hearing and taste.  From an evolutionary perspective these two senses are critical to survival behaviors after birth. Babies show a preference very early on for the voices of their mothers over voices of other females.

Researchers attribute this early recognition to the acoustical nature of the in utero maternal body.

While it has been shown that babies are able to hear the muffled sounds coming from outside of the mother’s body, the reverberations of the mother’s voice throughout the body increases the clarity of the auditory impact on the foetus. Evolutionists state that this serves the function of early bonding because babies will orient to their mother’s voice more quickly than that of anyone else.

It is not only the vocal quality that babies distinguish. Murphy Paul describes research relating to the earliest signs of tonal language development in infancy. Across cultures, babies will cry in the intonation of the language they are exposed to while in utero.

European babies with French speaking mothers will end their cries with a high-pitched intonation while European babies from German speaking mothers will end their cries on a downward pitch.

A groundbreaking experiment by Anthony DeCasper exemplified the discriminatory ability of infants’ acoustic recognition. DeCasper had mothers repeatedly recite Dr. Seuss’s The Cat in the Hat while pregnant. After birth, babies were able to select recordings that they could listen to by altering the speed of their sucking response on a nonnutritive nipple.

After a relatively short learning curve, babies consistently showed a preference for their mothers reading The Cat in the Hat by changing their sucking speed to elicit the familiar story.  Prenatal exposure led to a sensory preference outside of the womb.

The sense of taste also has powerful impacts on foetal development. Julie Mennellaconducted carrot juice exposure experiments on pregnant women. She included three conditions for carrot juice exposure:

• Women who drank carrot juice during pregnancy as a means of flavoring the amniotic fluid foetal taste receptors are exposed to.  These women switched to water after giving birth in order to ensure that their breast milk was not flavored by the juice.
• Women who drank water during their pregnancy and switched to carrot juice after pregnancy as a means of exposing the infants through breast milk.
• Women who did not drink carrot juice either while pregnant or thereafter.

Mennella found that infants exposed to carrot juice in utero exhibited less negative facial expressions at five months when introduced to carrot flavored cereal than babies in the control group.

Theorists site this prenatal sensory exposure learning as a sign of survivalist adaptability…flavors exposed to in utero teach an infant what is safe to consume both nutritionally and culturally after birth.

It is not strictly sensory exposure that offers learning potential for the foetus.  Rachel Yehuda discovered that the fallout from the 9/11 World Trade Center attacks did not end with the pregnant mothers in New York City.

In fact, the attacks affected foetal development with an increase in the incidence of a genetic PTSD biological marker in the infants of those women in their third trimester of pregnancy during the attack.  This particular marker is expressed through a hyperawareness to environment and a quick trigger response behavioral typing later in life.

Murphy Paul describes this research as a learning experience based on the necessary adaptability of the foetus to the outside world.

She explains that while it is important to recognize this is not a platform for “blaming the mother”, the mother does act as the narrator of the environment.  When the narration is inaccurate, the foetus may develop traits that make him or her ill equipped to handle the environment he or she is born into.

Therefore, while the hyper vigilance expressed through the activation of the PTSD marker may be conducive to babies born into war zones, it may not serve those born after an aberrant single exposure to a threat.

What is clear, however, is that the biological environment of the foetal experience is not to be discounted.  While we consider the in utero experience to be one characterized by a predominantly protective biological system, maternal experiences have a widespread and enduring impact on the foetus.

Image source: Meagan

Tagged developmental psychology, pregnancy