PSYCH 600 Week 2 Genetics, Prenatal Development and Early Biology Example

Pregnant During a Wildfire Evacuation: Prenatal Stress, Gene-Environment Interplay and What Early Biology Does and Does Not Fix

[Student Name]

University of Phoenix

PSYCH/600: Developmental Psychology

Week 2 Assignment

[Instructor Name]

[Date]

The family, the evacuation and the agency are composites written for a model paper; research findings come from the sources listed.

Parents often wonder whether something that happened during pregnancy shaped their child. Answering responsibly requires understanding how genes, the prenatal environment and early experience interact, and reading research carefully enough to avoid both false reassurance and false alarm. This paper addresses one such question from my work.

The Family's Question

Rosa Benally, a mother enrolled in our home visiting program in Tucson, was seven months pregnant when a wildfire forced her family to leave their home near Flagstaff. They stayed with relatives for three weeks, not knowing whether their house would survive. It did, but the family moved south soon after for work. Her daughter Mia, now four, is bright and verbal but anxious: she clings at drop-off, startles at loud sounds and has trouble sleeping. Rosa asked me whether the stress of the evacuation could have caused Mia's anxiety.

Genes, Environments and Heritability

Behavioral genetic research, mostly using twin and adoption designs, shows that many psychological traits, including anxiety, are partly heritable. Heritability is easy to misunderstand. It is a population statistic describing how much of the variation in a trait among people in a particular group and setting is associated with genetic differences. It says nothing about how much of one person's anxiety comes from genes, and it can change when environments change.

Turkheimer et al. (2003) showed this vividly. Studying seven-year-old twins from a national sample that included many families living in poverty, they found that the heritability of intelligence test scores depended on family socioeconomic status. In more affluent families, genetic differences accounted for much of the variation in scores; in poor families, genetic differences accounted for almost none, and shared family environment accounted for much more. Tucker-Drob and Bates (2016) later combined samples from several countries. American data showed the same income-dependent pattern, while samples from Western Europe and Australia, where public supports for poor families are stronger, did not. Their results suggest that environments can limit or allow the expression of genetic potential.

Gene-Environment Correlation and Interaction

Genes and environments are not independent. Parents pass on both genes and the home environment, so an anxious parent may pass on both a genetic tendency and anxious parenting. Children's genetically influenced traits also shape how others respond to them. These are gene-environment correlations. Gene-environment interactions occur when the effect of an experience depends on genetic makeup, or the reverse. For Mia, any genetic tendency toward anxiety and her experiences, before and after birth, work together rather than separately.

Prenatal Development and Stress

The prenatal period is a time of rapid development in which the fetus is sensitive to the mother's physical state, including nutrition, substances and stress hormones. Mia was exposed during the third trimester, when the brain grows rapidly and connections form.

Studying prenatal stress is difficult because stressed mothers may differ from others in many ways, such as income, health or genes. Natural disasters offer a partial solution because they strike randomly with respect to many family characteristics. Laplante et al. (2008) studied children whose mothers were pregnant during a severe 1998 ice storm in Quebec that left many families without power for weeks. Researchers measured the objective hardship each mother faced, such as days without electricity, and her subjective distress. At five and a half years, children whose mothers faced greater objective hardship had lower scores on measures of intelligence and language, even after controlling for factors such as education and postnatal life events. The effects were moderate, and timing mattered.

A disaster is a cruel experiment, but it is one researchers did not choose and families did not select into.

How Prenatal Stress Might Work

Glover (2011) reviewed research on prenatal stress and later child outcomes, including anxiety, attention problems and altered stress responses. Glover described possible mechanisms, including changes in the placenta's barrier to maternal stress hormones and in the regulation of the child's own stress system, and suggested from an evolutionary perspective that prenatal signals might prepare a child for a threatening world by increasing vigilance. Glover emphasized that most children exposed to prenatal stress develop normally, that effects are modest and that they can be modified by sensitive postnatal care.

Epigenetic changes, chemical modifications that affect how genes are expressed without changing DNA sequences, are one proposed pathway. Much of this evidence comes from animal studies, and human findings remain tentative, so it would be wrong to tell Rosa that the evacuation "changed Mia's genes."

Other Prenatal Influences Worth Ruling Out

Stress was not the only prenatal factor worth considering. I asked Rosa, gently and as part of our routine intake review, about other exposures during pregnancy. She had taken prenatal vitamins, did not smoke or drink and had no serious illnesses, though she said she ate poorly during the three weeks away from home and slept little. Smoke exposure from the fire itself is another possible influence; research on wildfire smoke in pregnancy is still developing, and it has mostly examined birth weight and preterm birth rather than later behavior. Mia was born at full term with normal weight. Ruling out these factors does not identify a cause, but it narrows the list and keeps the conversation from settling too quickly on the most dramatic explanation. It also models for Rosa how professionals reason: by gathering facts before drawing conclusions.

Weighing the Evidence for Mia

Several explanations for Mia's anxiety fit the evidence. The prenatal stress of the evacuation may have played a role. Mia may have inherited a tendency toward anxiety; Rosa describes herself as a worrier. The family's later move, Rosa's ongoing stress and the startling sounds of a new city neighborhood are postnatal influences. These explanations are not exclusive, and research cannot say how much each contributes in one child.

What Early Biology Does Not Fix

The research also gives reason for hope. Development remains plastic, and early care can buffer risk. Sensitive, predictable caregiving helps children regulate stress, and anxiety in young children responds well to supportive interventions. The finding that environments shape whether genetic potential is expressed applies here too: Mia's environment now matters a great deal.

What I Told Rosa and What We Did

I told Rosa that research does link severe stress during pregnancy with some differences in children, that the effects are usually modest, that many factors contribute to anxiety and that nothing she did caused harm. I emphasized that what she does now, keeping routines predictable and responding calmly to Mia's fears, can make a real difference. We agreed on a bedtime routine, gradual practice with separation at preschool and a referral to the agency's early childhood mental health consultant.

Conclusion

Genes, the prenatal environment and early experience shape development together. Research on prenatal stress from natural disasters provides some of the strongest evidence that the womb environment matters, but it also shows modest effects that later care can modify. Heritability itself depends on the environment. Explaining these ideas carefully allows professionals to answer parents honestly without assigning blame or predicting destiny.

References

Glover, V. (2011). Annual research review: Prenatal stress and the origins of psychopathology: An evolutionary perspective. Journal of Child Psychology and Psychiatry, 52(4), 356-367. https://doi.org/10.1111/j.1469-7610.2011.02371.x

Laplante, D. P., Brunet, A., Schmitz, N., Ciampi, A., & King, S. (2008). Project Ice Storm: Prenatal maternal stress affects cognitive and linguistic functioning in 5 1/2-year-old children. Journal of the American Academy of Child & Adolescent Psychiatry, 47(9), 1063-1072. https://doi.org/10.1097/CHI.0b013e31817eec80

Tucker-Drob, E. M., & Bates, T. C. (2016). Large cross-national differences in gene x socioeconomic status interaction on intelligence. Psychological Science, 27(2), 138-149. https://doi.org/10.1177/0956797615612727

Turkheimer, E., Haley, A., Waldron, M., D'Onofrio, B., & Gottesman, I. I. (2003). Socioeconomic status modifies heritability of IQ in young children. Psychological Science, 14(6), 623-628. https://doi.org/10.1046/j.0956-7976.2003.psci_1475.x