How Trauma Gets Passed to the Next Generation | NOVA | PBS

PBS NOVA
PBS NOVAApr 27, 2026

Why It Matters

Understanding that trauma can be biologically inherited and that our sense of agency is malleable reshapes approaches to mental‑health care, preventive interventions, and the ethical use of brain‑stimulation technologies.

Key Takeaways

  • Trauma can alter gene expression across generations via epigenetics.
  • Mice exposed to odor‑shock produce more almond receptors in offspring.
  • Human studies show famine survivors' grandchildren inherit metabolic issues.
  • Brain stimulation reveals our sense of agency can be illusory.
  • Perceived control may be overridden by unconscious neural processes.

Summary

The video explores how traumatic experiences can be biologically transmitted to subsequent generations, combining historical human data with cutting‑edge animal research and neuroscience experiments on perceived control.

Researchers cite the Dutch famine of WWII, where children and grandchildren of starving survivors exhibit metabolic disorders, suggesting epigenetic inheritance. In the lab, biologist Bianca studies mice, pairing almond scent with a mild shock; exposed mice develop more almond‑responsive olfactory cells, and this heightened receptor expression persists in their offspring, indicating a germ‑line memory of stress.

The program also features neuroscientist Uri Maoz’s demonstration that the feeling of agency can be manipulated. Using transcranial magnetic stimulation, participants’ finger movements are triggered milliseconds before conscious awareness, leading subjects to doubt whether they initiated the action. “That wasn’t me,” one volunteer says, highlighting the fragility of self‑perception.

These findings suggest that both inherited biological changes and moment‑to‑moment neural processes undermine the illusion of full personal control, with implications for mental‑health treatment, public‑policy on trauma, and ethical considerations in neuromodulation technologies.

Original Description

The past might be closer than we think. Scientists have found that experiences — especially stress and trauma — can change how genes are expressed, and in some cases, influence future generations.
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