There is increasing evidence that traumatic experiences leave traces in our genetic makeup. An exemple is developed in the article (in French) ‘Childhood abuse leaves scars in the DNA‘; this is also true of other forms of stress – for example this article from the US American Psychological Association ‘How chronic stress is harming our DNA‘
This has been observed for a decade now in particular regarding the expression of certain genes, and in general epigenetic changes, which can be transmitted although they don’t change the overall DNA codes. Those changes are deeper when stress is stronger and more repeated. There is now proof that these can be transmitted to children, but also that they can in a certain manner be reversible, as proven by certain studies on post-traumatic stress disorder and the actual impact of psychotherapy.
In the field of chamanism and trance, it is considered known that people can bear within themselves the consequences of acute stress suffered by one’s ascendants and some ceremonies are designed to manage this situation.
DNA expression modification linked to one’s environment is all quite a new investigative domain with interesting consequences on the eternal topic of determination and choice. Expect more to be understood and written on that topic in the next years!