The highly anticipated movie Assassin’s Creed relies on the premise that memories can actually be transmitted across generations through DNA, just like the video game on which it’s based.
In the movie, the protagonist experiences the memories of a 15th-century assassin ancestor and gains the knowledge and skills to battle an age-old enemy in the present day.
While this sounds like a fascinating plot for a fantasy action movie, is there any scientific backing for the idea that the experiences of our ancestors can be stored in our DNA?
Discover’s “Trait vs Fate”
An article entitled “Trait vs. Fate” in the May 2013 issue of Discover magazine weighs in with a scientific perspective, looking at breakthrough scientific discoveries over the last few decades.
Geneticists in the 1970s made a surprising discovery: Environmental factors such as diet and exposure to chemicals could alter gene activity without altering the genetic code through the addition of methyl groups, which attach to the DNA (in a process known as DNA methylation).
What was even more surprising was this finding: Methyl groups, which alter gene expression, could be passed down along with the genes to subsequent generations.
That’s a huge revelation. It means the life experiences of one generation, like changes in diet or exposure to chemicals, could lead to changes in gene activity — AND these changes could be passed down to subsequent generations.
Stress & Neglect Can Impact Gene Activity
Next scientists wondered: Could additional environmental factors that are experience-related, such as neglect or stressful situations, also impact gene activity?
Dr. Moshe Szyf and Dr. Michael Meaney conducted multiple studies to determine this. After separating female rats into groups based on their (extremely good or bad) mothering abilities, they studied the genes of their offspring. A second experiment saw the offspring raised by the opposite group than their birth group. A third study examined offspring given a drug to remove inherited behavioral deficits.
The overall results demonstrated that, without changes to their actual genetic code (through changes known as epigenetic changes), the genes of the offspring functioned differently due to their upbringing.
Rats raised by bad mothers grew up to be nervous wrecks, as a result of methyl groups attaching to their genes regulating the production of glucocorticoid receptors, which regulate sensitivity to stress hormones.
Ancestors’ Experiences Echo in the Next Generation…
Additional studies have looked into whether these changes in genetic function can be passed down through generations. The question was: Could the stressful experiences of your ancestors echo in your life, a sort of DNA-associated “memory”?
Neuroscientist Eric Nestler of the Icahn School of Medicine at Mount Sinai in New York, for example, learned that male mice who had been bullied by larger, more aggressive mice had offspring that were hypersensitive to stress.
A study by Dias and Ressler in Nature Neuroscience, found evidence that if the scientists taught mice to fear the scent of the chemical acetophenone through the use of electric shock, the next generation would be extra sensitive to the chemical’s cherry-blossom-like scent as well.
…But Here’s the Final Verdict
However, no consensus around any of these studies has emerged.
Thus, when it comes to the question of whether the experiences of one generation affect the behavior of the next, the answer appears to be maybe.
But it’s unclear how long that effect lasts, and it probably doesn’t apply to behaviors, like memories, that aren’t determined by our genes.
What is definitely known is that genes themselves are passed down from generation to generation and that they contain information that affects who you are.
You may not have inherited memories that tell you where all of your ancestors lived hundreds of years ago. But your genes carry the signature of your ancestry.
What do your genes know that you don’t? Take an AncestryDNA test to find out.