Maternal Emotions and Human Development

For nearly a hundred years, we have been enslaved with the notion that our fate is locked in our genes. This vision, grounded in the dogma of traditional medical sciences, perceives that organismal development represents a simple read-out of inherited genetic programs. The dogma, officially couched as the "primacy of DNA," concedes that genes play a causal role in controlling biological expression and behavior by their ability to turn themselves on and off. This perspective on the role of genes has lead to the concept of "genetic determinacy," the idea that our lives are predetermined by the hard-wiring of gene programs. Whenever deviations in behavior or alterations in physiology arise, genetic determinists immediately attribute them to genetic defects or mutations.

Proponents of genetic determinacy claim that our physiological and behavioral expressions are determined once the genes of the sperm and egg come together at the moment of conception. According to this mechanical view, maternal "nurturing" of the fetus is simply limited to providing appropriate metabolic support. This traditionalist dogma, which attributes little significance toward a pre- and perinatal "environmental impact" upon human development, has been radically challenged by recent advances in cell research.

In contrast to the beliefs of genetic determinacy, it is becoming evident that organismal expression is dynamically and intimately intertwined with environmental cues. Genes in the nucleus do indeed represent blueprints for proteins, the molecules responsible for physical traits and the mechanics underlying behavior. However, it is now recognized that the regulation of gene expression, that is the switching on and off of genes, is not a property of the genes themselves, but is controlled by environmental signals (Nijhout, 1990). We are also now aware of the fact that organisms under stress are able to actively alter their DNA and create new genes in an effort to accommodate environmental challenges (Thaler, 1994). Rather than being genetically predetermined, organisms develop in balance with their environment and purposively select, or if necessary rewrite, what they perceive to be appropriate gene programs to ensure their survival.

An article in Science entitled "A New Look at Maternal Guidance" (Pennisi, 1996) reveals that parents pass more than genes on to their offspring. The report acknowledges that the parent’s provide non-genetic contributions that dramatically influence the development of the offspring and have profound ecological and evolutionary implications. Studies cited reveal that maternal contributions can enhance an offspring’s chances for survival and even influence a species’ ability to adapt to its environment. Recent evidence reveals that even though a child may be afflicted with specific genetic defects, the degree of the defect’s "expression" may be highly variable. For example, Tourette’s Syndrome, which produces severe motor and vocal tics, is due to the presence of a single dominant defective gene. However, the degree of severity of the gene’s defect is variably expressed. The observed range of expression is now recognized to be regulated by non-genetic factors, including prenatal environmental influences (Wolf, et al., 1996).

"Maternal effects provide a powerful avenue for [altering] the course of the future by adding information content and material content. That content can be…anything that can influence how an embryo develops" [ibid]. In regard to influential material content, the role of the mother’s biochemistry in fetal development is well known. We are particularly sensitive to the importance of maintaining appropriate nutritional status during pregnancy. The focus of more recent investigations has drawn public attention to the debilitating nature of maternal toxins and drugs, such as cigarette smoke, alcohol and crack cocaine.

Most everyone is in some way familiar with the impact that the mother’s material (chemical) content has upon human development. However, very few are aware that the mother also passes on information content to the fetus during pregnancy. The information relayed by the mother to the fetus concerns the status of the environment. This status is conveyed in the mother’s perceived attitudes about life. The mother’s emotions, such as fear, anger, love, hope among others, can biochemically alter the genetic expression of the offspring. Our perceptions of the environment, and their attendant emotions, elicit physiological responses in the body by releasing "signal" molecules into the blood. Blood-borne emotion-related signals activate specific receptor proteins on the surfaces of cells in tissues and organs. Activated receptors serve as molecular switches that adjust the metabolic system and behavior of the organism, so as to accommodate environmental challenges. Physiologic responses to environmental signals include regulations of the nervous system, endocrine organs, and the cardiovascular, respiratory, digestive and excretory functions.

During pregnancy, the parent’s perception of the environment is chemically communicated to the fetus through the placenta, the cellular barrier between the maternal and fetal blood. The mother’s blood-borne emotional chemicals cross the placenta and effect the same target cells in the fetus as those in the parent. Though the developing child is "unaware" of the details (i.e., the stories) evoking the mother’s emotional response, they are aware of the emotion’s physiological consequences and sensations.

While developing in the safety and confinement of the uterus, the child is provided a preview of the environment as it is defined by the parent’s perception and behavior. Parental behaviors are generally cyclic, and when repeated, they serve to habituate the developing behavioral chemistry in the fetus. Consequently, parental perceptions and responses to environmental stress are imparted to the offspring and serve in programming its behavioral expression.

Behavioral "memories" are in part related to the appearance of specialized cell and tissue protein receptors which serve as "filters" in remembering past signals. Behavioral "filters" acquired during pre-and perinatal "programming" are Nature’s way of preparing the neonate to function in the parent’s environment. Technically, these "learned" filters would enable the child to adapt more quickly and successfully to the home environment. The parents’ experiences help "preprogram" the behavior of the child, so that it may more effectively deal with environmental exigencies.

It is important to note that individual events of parental anger and fear do not necessarily distort the "physiology" of the developing child. It is specifically "chronic," or continuously held emotions that prove to be detrimental during pregnancy. For example, parents that did not wish to have a child, parents that are continuously concerned about their own and consequently their offspring’s chances for survival, women who sustain physical and emotional abuse during their pregnancy all represent situations where adverse environmental cues surrounding the birth of their child can be passed on to the offspring. These are all cases of repeated, or patterned, abuses which is entirely distinct from parents that express a transient occasional spat or emotional peak. It should be noted that the behavioral consequences of children exposed to negative or destructive attitudes during their prenatal developmental can be psychologically reversed, once the issues are recognized.

In this new perspective, parental nurturing is obviously more than just providing metabolites and a safe haven for development. Nurturing is profoundly more inclusive in that the parent’s attitudes and perceptions help prepare the baby in learning to deal with its new environment. The survival advantage offered by prenatal "programming" is quite obvious. Unfortunately, most parents are completely unaware that their emotions and behaviors are being passed on to their children during pregnancy. Consequently, sustained parental anger and fear compromise the child’s development and health, as the emotional stresses chemically impact the fetus. In utero, the child acquires "attitudes" about life as it decodes the "behavioral" signals relayed in the blood. We are all clearly aware that emotional chemistry obviously affects our strengths and our weaknesses. When relayed to the developing child, the same chemistry will similarly impact the fetus.

New research regarding maternal and environmental influences on gene expression urgently underscores the need for us to recognize the concept of "conscious parenting." In conscious parenting, the concept of a "family" becomes a reality from the moment of conception. Parents must be consciously aware that from the idea of conceiving a baby and all the way through its pre- and postnatal development, their thoughts, attitudes and behaviors will profoundly influence their child’s development and health.

References: 

Nijhout, H. J., (1990). Metaphors and the role of genes in development, BioEssays 12, 441-446
Thaler, D. S., (1994). The evolution of genetic intelligence, Science 264, 224-225.

Pennisi, E., (1996). A new look at maternal guidance, Science 273, 1334-1336.

Wolf, S. S., et al., (1996). Tourette Syndrome: Prediction of phenotypic variation in monozygotic twins by caudate nucleus D2 receptor binding, Science, 273, 1225-1227. I