An important question here are whether we're talking about immutable genetic encoding vs genetic expression (sometimes more controversially known as "epigenetic

An important question here are whether we're talking about immutable genetic encoding vs genetic expression (sometimes more controversially known as "epigenetics"), which is mutable via environmental stimuli, experiences, beliefs, traumas, cultural influences, etc. The follow-up question to that is the extent to which one's epigenetic state at birth is determined during gestation and influenced by the mother's beliefs and experiences (as well as the father's indirectly via the mother). This would explain why some correlations are found in twin study results, but also why those correlations are never close to 100%. It would also explain the study results that suggest inheritance of patterns like trauma/anxiety e.g., in descendants of holocaust survivors. I'm fully aware this area is nascent and yet to be deeply researched, but hypotheses exist that are plausible and potentially explanatory of phenomena that are otherwise still unexplained.