Trauma is in your DNA, but early biological imprints can be changed

Though your environment affects your genes, the outcome is not permanent.

- By Tara-Lyn Camilleri

As war rages in Gaza and Ukraine, there is concern about how the trauma might be transmitted to future generations of people in those regions.

More generally, interest in the idea of transgenerational trauma has recently surged. For example, earlier this year, National Geographic magazine asked whether genes carry past family trauma.

But although this might be a catchy question, it's also slightly misleading. Because although trauma can ripple across generations, shaped by how our bodies respond to their environments, its effects aren't hardcoded in our genes.

Plastic minds and bodies

At the heart of this process is what's known as phenotypic plasticity. This is the capacity for organisms to produce different outcomes from the same genes, depending on their environment. These outcomes, called phenotypes, can include stress sensitivity and body shape.

One way different phenotypes can arise from the same genes is via epigenetics: small chemical changes to the DNA molecule that make particular genes more or less active. Think of these like a director's notes on a script. These notes guide the cell on which lines to emphasise or soften, without changing the script itself.

The effects of trauma are better understood as changeable responses shaped by context

But epigenetics is just one way this plasticity is expressed. Understanding how trauma is passed across generations means looking beyond genes and cells to the environments that shape and influence them.

Human development is sculpted by lived experience, from caregiving and community to stress, safety and belonging.