For a long time, it was believed that a person’s experiences ended with their own biological life. However, recent research suggests that certain events of trauma could leave marks on gene expression that influence the health of later generations. Epigenetics offers a possible scientific explanation for this phenomenon.

The concept of intergenerational transmission of trauma

The idea that trauma can influence future generations has become a growing area of research in recent decades. According to the scientific article Intergenerational transmission of trauma effects: putative role of epigenetic mechanisms published in the journal World Psychiatry, some effects of extreme stress could be passed from parents to children through biological mechanisms related to epigenetics.

Epigenetics studies how environmental factors such as stress, violence, malnutrition, or experiences of trauma can modify how certain genes are activated or deactivated. These modifications do not change the DNA sequence itself, but they do influence how the body uses its genetic information. In other words, they act like chemical switches that regulate gene activity.

Researchers have observed that children of people who experienced severe trauma—such as wars, persecution, or famines—may show changes in biological systems related to stress or metabolism. For example, some studies have found differences in the hormonal regulation of the hypothalamic–pituitary–adrenal axis, a key system in the body’s response to stressful situations.

However, scientists emphasize that the intergenerational transmission of trauma can occur through multiple pathways. Not only biological factors are involved, but also psychological, family, and social elements. For this reason, researchers believe that epigenetics may represent only one part of a much more complex process connecting the experiences of one generation with the health and behavior of the next.

Scientific evidence and studies investigating the phenomenon

Much of the research on the transmission of trauma comes from animal studies, where scientists can carefully control environmental conditions. In some experiments, researchers have observed that stressful experiences in parents can influence the behavior or physiology of their offspring, even when the offspring have never encountered the original stimulus.

These findings suggest that certain epigenetic markers may be transmitted through reproductive cells such as sperm or eggs. Such changes can affect the regulation of genes associated with stress, fear, or adaptation to the environment.

In humans, research is more complex. The article from BBC Future on this topic notes that scientists have studied populations exposed to extreme events such as wars, persecution, or periods of severe famine. Some studies have found biological differences in the descendants of people who experienced these events, which has fueled the hypothesis of a possible intergenerational transmission of trauma.

Even so, demonstrating a direct epigenetic mechanism in humans remains difficult. Researchers must consider many variables such as education, family environment, nutrition, or social context, all of which also influence people’s health and development.

For this reason, most scientists describe these findings as emerging evidence, rather than a definitive conclusion.

What science knows today and what is still debated

Today, the scientific community agrees that the environment can influence gene expression through epigenetic processes. This represents an important shift from the traditional view of genetics, which considered DNA to be a relatively fixed system.

However, debate continues about the extent to which these changes can be transmitted across generations in humans. Some researchers argue that epigenetic marks may disappear during the biological processes that occur during embryo formation, which would limit their long-term inheritance.

Other scientists suggest that certain changes could persist under specific circumstances, especially when experiences of trauma affect fundamental biological systems such as metabolism or the stress response.

The current consensus is that the intergenerational transmission of trauma is likely the result of interactions between biological, psychological, and environmental factors. Rather than a direct inheritance of trauma, what may be passed on is a greater sensitivity or vulnerability to certain conditions.

Understanding these mechanisms is important not only for scientific research but also for improving mental health strategies, prevention, and treatment of the effects of trauma across generations.

Research on the intergenerational transmission of trauma suggests that human experiences may have broader effects than previously thought. Although epigenetics provides important clues, science is still investigating how biology and the environment interact. Understanding these processes may improve how we address the long-term effects of trauma.

Referencia: 

World Psychiatry/Intergenerational transmission of trauma effects: putative role of epigenetic mechanisms. Link

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