More complicated and controversial are the results suggesting Hitler may have had one or more neurodiverse or mental health conditions.
Looking at his genome, and comparing it with polygenic scores, they found that Hitler had a high predisposition for autism, ADHD, schizophrenia and bipolar disorder.
This is where the science gets complex.
Polygenic scoring combs through a person’s DNA and calculates how likely they may be to develop a disease. It can be useful to detect an individual’s predisposition to conditions like heart disease and common cancers. But it compares their DNA with a large population sample, and therefore the findings can be far less certain when it comes down to an individual.
Throughout the documentary, which the BBC has seen, the experts are at pains to reiterate that the DNA analysis is not a diagnosis, but an indication of predisposition – it does not mean Hitler had any of these conditions.
But some genetic scientists have raised concerns that the findings are an oversimplification.
Denise Syndercombe Court, professor of forensic genetics at Kings College London, feels they have “gone too far in their assumptions”.
“In terms of character or behaviour, I’d have thought that’s pretty useless,” Prof Court, who tested the same blood sample in 2018, told the BBC.
She said she wouldn’t want to make any predictions as to whether someone had a particular disease from the results, because of “incomplete penetrants”.
Put simply, by fellow genetic scientist Dr Sundhya Raman: “Just because you have something encoded in your DNA, doesn’t mean you’ll express it.”
This is reflected in the documentary by Prof Simon Baron-Cohen, director of the Autism Research Centre at Cambridge University: “Going from biology to behaviour is a big jump,” he says.
“By looking at genetic results like this, there’s a risk of stigma. People out there might think, ‘Is my diagnosis being linked to somebody who did such monstrous things?'”
“The risk is reductionism down to genetics,” he says, when there are so many other factors to consider.
