Here actually read what the research is telling us and you’ll understand that you aren’t afraid of butterflies because your ancestors were attacked by a swarm of butterflies in the past. That just sounds ridiculous doesn’t it?

Just wanted to make this into it’s own post. Sorry to do this again, wildcat2030, but there’s just so many people commenting saying this explains their fear of (insert noun) and they need to know what’s actually going on. Original discussion here.


Phobias may be memories passed down in genes from ancestors

Memories may be passed down through generations in DNA in a process that may be the underlying cause of phobias

Memories can be passed down to later generations through genetic switches that allow offspring to inherit the experience of their ancestors, according to new research that may explain how phobias can develop. Scientists have long assumed that memories and learned experiences built up during a lifetime must be passed on by teaching later generations or through personal experience. However, new research has shown that it is possible for some information to be inherited biologically through chemical changes that occur in DNA. Researchers at the Emory University School of Medicine, in Atlanta, found that mice can pass on learned information about traumatic or stressful experiences – in this case a fear of the smell of cherry blossom – to subsequent generations. The results may help to explain why people suffer from seemingly irrational phobias – it may be based on the inherited experiences of their ancestors. (via Phobias may be memories passed down in genes from ancestors - Telegraph)


This post is really misleading and explains it in a way that’s far from the truth about what’s really (possibly) happening. The future generations aren’t getting “memories”, but rather, an inherited sensitivity of sorts.

Note: In the quote below, F1 refers to the first generation of offspring from the parent taught to fear the smell, and F2 is the second generation.

from National Geographic:

The scientists then looked at the F1 and F2 animals’ brains.  When the grandparent generation is trained to fear acetophenone, the F1 and F2 generations’ noses end up with more “M71 neurons,” which contain a receptor that detects acetophenone. Their brains also have larger “M71 glomeruli,” a region of the olfactory bulb that responds to this smell.

This is far from a memory.

From ArsTechnica:

We’ve identified a few forms of epigenetic inheritance—primarily chemical modifications of DNA—that can be changed during the life of an organism but can still be passed down to its progeny.

Mice can be taught to fear the smell of a specific odorant simply by giving them electric shocks whenever they’re exposed to it. It’s then simple to read out the strength of this through a startle response. When they hear a loud noise, mice tend to freeze for a short period of time. If you hit them with both a loud noise and the odor they fear, they’ll freeze for even longer.

Rather than testing the mice themselves, however, the researchers decided to test their offspring. And they found that mice in the next generation, as well as the generation after that, also showed an enhanced startle effect when exposed to the same chemical. They ruled out the simplest explanation for this—researcher bias—by making sure that the person measuring the response was blinded to whether the mouse they were testing was an experimental animal or a control.

And, in an even more concise way to say it’s not a memory, nor is it a phobia per se,

In other words, the parental exposure and training seemed to prime offspring to be able to perceive the odor much more easily.

So, yes, while this is an amazing scientific discovery—if further research confirms these findings—it’s a far more subtle biological change that’s occurring. The results show that it’s sensory sensitivity to a stimulus that’s being passed down, and that’s a pretty big leap from memories, phobias and “inherited experiences of their ancestors.”

This is what I was thinking too. The mice were just being trained to be more sensitive to the odors, by up-regulating certain odor-receptors, allowing them to have a better/faster reaction to what they perceived to be a ‘bad smell’. Like how we humans do not like the smell of rotten eggs, or Hydrogen Sulfide, because we have a sensitivity to it since it is toxic.

Very far from Assassin’s Creed (so stop with that AC-hype BS) and really any phobias like fear of clowns or spiders and some people were saying it explained Islamophobia (ridiculous!). Those are a result of the brain interpreting visual stimulus and gene regulation has very little influence in something like that. — Your eyes can’t tell the difference between a photon that bounced off a spider or an Islamic person. — Those phobias are more a result of your childhood upbringing and how society framed them for you, causing certain neural pathways to be reinforced, leading to the phobia.

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