This article claims that the children of Holocaust survivors are known to have increased likelihood of stress disorders.
The team was specifically interested in one region of a gene associated with the regulation of stress hormones, which is known to be affected by trauma.
“It makes sense to look at this gene,” said Yehuda. “If there’s a transmitted effect of trauma, it would be in a stress-related gene that shapes the way we cope with our environment.”
They found epigenetic tags on the very same part of this gene in both the Holocaust survivors and their offspring, the same correlation was not found in any of the control group and their children.
The team ruled out the possibility that the epigenetic changes were a result of trauma that the children had experienced themselves.
“This provides the first demonstration of transmission of pre-conception stress effects resulting in epigenetic changes in both the exposed parents and their offspring in humans.”
Other studies have proposed a connection between one generation’s experience and the next.
For example, girls born to Dutch women who were pregnant during a severe famine at the end of the second world war had an above-average risk of developing schizophrenia.
Likewise, another study has showed that men who smoked before puberty fathered heavier sons than those who smoked after.
And scientists at Emory University in Atlanta trained male mice to fear the smell of cherry blossom by pairing the smell with a small electric shock. Eventually the mice shuddered at the smell even when it was delivered on its own.
Despite never having encountered the smell of cherry blossom, the offspring of these mice had the same fearful response to the smell - shuddering when they came in contact with it. So too did some of their own offspring.
On the other hand, offspring of mice that had been conditioned to fear another smell, or mice who’d had no such conditioning had no fear of cherry blossom.
See also: Can you inherit trauma?