Can you inherit memories from your ancestors?

I read the article, the linked study, and two studies citing the linked study. The claim that memories or “lived experience” is inherited is not supported by the study.

Erm…memories — by any biologically reasonable definition— are separate from epigenetic changes. No serious researcher would conflate the two, other than perhaps hippy-dippy ‘biologists’ who struggled through ‘Physics for Poets’, as undergrads. Source: Biophysicist for 30 years now.

There’s a big difference between DNA methylation on gametes leading to behavioral predispositions in offspring and the claim that memories and experiences are inherited.

Instinct is totally different from memory.

Well, you've got brain wiring that causes you to respond to stimuli in a certain way. A small portion of that wiring is genetic (e.g. opposite sex attraction, fear of heights, disgust at certain smells), and the rest comes from prior sensory exposure (i.e. is learnt during your own lifetime).

just look up dna methylation

It seems pretty clear for example that being an alcoholic can cause DNA methylation in your gametes such that your offspring have a higher risk above and beyond regular genetic factors to become an alcoholic. However that is at a population level and there are complicating factors.

Inherited trauma is totally unsupported but up or down regulated gene expression based on environmental factors before your conception are supported by some compelling evidence.

The basic idea is that genome modifications can be inherited with the genome. Methylation is one example; histone mods are another. If you want specific examples, I'd recommend focusing on a specific type of modification and searching "fill-in-the-blank inheritance", to avoid the more dramatic pop science.

I'm in a comp bio PhD studying epigenetics in development and disease. Epigenetics can be thought of as the set of biochemical mechanisms other than the linear sequence of DNA that store and respond to information to control cell behavior. This is how normal development from a single zygote to an adult organism is controlled, why cells vary so much despite having (mutations/mosaicism aside) the same DNA, how cells respond to changing biochemical conditions, and where cancer comes from.

The classic example of epigenetics - of stable information transfer between cell generations not based on DNA sequence - is methylation of cytosines. Here's the simplified version. As you know, the DNA is based on ACTG. When you have a CG, the C can be methylated, which means an extra carbon is attached at a specific position on the molecule. That extra carbon gets 'copied' when the DNA is duplicated during mitosis and gets passed to the daughter cells. Yet it can be added or erased during the cell's lifetime. It typically works to block proteins responsible for transcribing genes into mRNA from binding to the gene, so the gene is silenced when it is methylated. This gives a way to transmit patterns of gene expression across generations of cells.

This mark is extremely well-studied and understanding everything about DNA methylation is beyond this humble PhD student. But there are also extremely mechanisms for erasing and/or resetting certain aspects of cell state during mitosis or meiosis, including RNA, the proteome, and methylation state. We can't take it for granted that just because there's a mechanism by which biochemical information could be transmitted that it actually is (or that it isn't).

A common source for the idea of intergenerational trauma being supported by epigenetic evidence is the Dutch hunger winter [1]. The idea is that an experience that parents had in utero seems to have had an effect on the physical development of their children, in a way that's specific to parental sex. I'm willing to say "sure, that effect could be real and there could be an epigenetic explanation." But AFAIK we don't know specifically what that hypothetical mechanism would have been.

Note that the bod(y|ies) of the mother and child are interchanging material and engaging in biochemical crosstalk constantly during gestation, so there is abundant opportunity for environmental influences on the mother to have lifelong impacts on the child. Since the child's body will in turn engage in the same 'dialog' with the child's own children during fertilization and gestation, it's entirely possible for environmental influences on generation 1 to impact generation 3 as mediated by generation 2 via an in utero exposure.

All that said, I have a lot of uncertainty about what our priors ought to be on how important such hypothetical mechanisms might be. I think that in the coming decades, we'll make huge progress in understanding development and disease within an individual's body through an epigenetic lens. We will probably also see some interesting controlled experiments on "epigenetic inheritance" using short-lived model organisms, such as fruit flies or worms. Possibly we will collect enough epigenetic information in large-scale biobanks over 20-40 years that we can get a more detailed understanding of possible epigenetic inheritance mechanisms in humans, but these assays are currently quite expensive, and moreover there's no single measure applicable to an individual person, since the whole point of epigenetics is that the state varies across cell and tissue type.

[1] https://www.ohsu.edu/school-of-medicine/moore-institute/dutc...

I can not look into my genes so I know nothing about that, but what I can say with confidence is that trauma therapy continues to fundamentally change how I judge, act and react, and has deeply positive effects on all my relationships. I can totally see how that positively influences how my children will develop. That aspect of “passing on trauma“ is very real. I now stay calm and regulated in most stressful situations, and in the few cases where I overreact I know how to and I have the ability to (!) make up for it later and correct my mistakes. And use the trigger to further heal past pain.

Definitely. People want to believe it so badly that they'll just throw all logic out the window. I can't find it with a cursory search, but I recall one case in which a person allegedly inherited a fear of drowning via "genetic memory" from her uncle who drowned shortly before she was born. It's essentially "psychic medium" bullshit with a veneer of pseudobiology. But hoo boy, does that ever play well.

It's one thing to suggest that psychological or metabolic stress could affect the dynamics of DNA methylation in a way that crosses generational boundaries. It's quite another to identify those inherited dynamics as "memories".

It's easy to mistake upbringing with something inherited, or culture and behaviour with familial / race / appearance. I'm sure THAT part is partially inherited (same with the pattern recognition mentioned above).

There's an idea of 'fixed action patterns' where certain behaviors are encoded in the neurology of an animal, and triggered by certain stimulus.

For spiders then there is an action pattern that upon certain stimulus they will use their spinnerets begin forming a web, first placing anchor points and gradually building it up with radial threads and spiral. The exact behavior differs by species such that they have different resulting patterns. It seems possible that there is an element of 'learning' beyond the basic pattern as well, even in seemingly very simple animals.

I doubt the spiders have a mental model of what their web looks like as such, it's more evolutionary driven genetic behavior, a particular neuronal pattern encoding the action sequence rather than an underlying fundamental understanding.

Sidenote: My brother the biologist tells me that cats do not instinctively understand that heights can be dangerous; they have to learn it by trial & error.

Most DNA is non-coding and encodes tweaks to which genes are expressed where and how. The same way evolution evolved reliable formation of complex body arrangements out of stochastic molecular processes and variations in gene expression based on location, nearby cells and their own signalling, it's done the same for neurons which are far from a homogenous mixture and thus can learn some things("instinctual behaviour") easier than others, all the way to it happening essentially automatically.

> People say 'instinct' by never mention what that means or how it works :-P

Have you never been afraid of spiders or snakes?

https://www.cbs.mpg.de/Fear-of-spiders-and-snakes-is-deeply-...

I don't think this isn't fully known. Neural science has long been a fascination of mine and the conclusion I've come to is that it can happen in two ways.

The first is direct. In order for this to happen there must be a stable representation of the input and output. In this case, bright colors must have a stable representation, and fear must have a stable representation. This gives the opportunity for neurons to know how to connect the two so that one leads to the other. How does the individual neuron do that? The body is full of chemical gradients and they function kind of similar to landmarks that can be used for navigation by the growing neuron.

The second is indirect. In this case there is nothing directly encoding the connection between brightness and fear, instead due to factors of the brain structure and the environment the animal exists in it is highly likely to learn the association. For instance the low-level visual processing and fear processing areas of the brain may be almost but not quite wired up. Now there may be a common insect that is brightly colored and just a little bit poisonous. Due to the innate curiousity the animal will try to eat the insect and get an upset stomach. The dormant connection is then molded to associate these two things.

> I don't see any connection between the Guardian and the recovered memory movement.

It’s a comparison.

Respected or not she’s making the argument the “the body keeps the score,” which is redolent of the discredited book of the same name.

I only knew this existed because of the "left" take with regards to people descended from slaves (black only of course)

> The left don't think that trauma can be inherited.

The epigenetic reaction to trauma is something that may be able to be inherited.

Epigenetic transmission of Holocaust trauma: can nightmares be inherited? - https://pubmed.ncbi.nlm.nih.gov/24029109/

Study finds epigenetic changes in children of Holocaust survivors - https://www.research.va.gov/currents/1016-3.cfm

How Parents’ Trauma Leaves Biological Traces in Children - https://www.scientificamerican.com/article/how-parents-rsquo...

Mechanisms of Epigenetic Inheritance in Post-Traumatic Stress Disorder - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10817356/

(Not trying to pose this as a left/right thing - but rather "this is a thing" - and these aren't memories but rather the result of epigenetic changes to the expression of hormones and neurotransmitters that may be able to be passed from mother to child and exhibit differences in how one reacts to certain stimuli)

> The left don't think that trauma can be inherited.

Well, some of them do, as otherwise they would not have told me about it at length in conversation. Scientific literacy varies greatly within every political camp.

I don't know if you can speak for the entire left here, it's really not hard to find articles from the 2010s from otherwise fairly respectable progressive publications which are pretty confident. Usually when I've heard ideologically minded people talking about "transgenerational trauma" [1], it's from a lens of epigenics. I don't think anyone would reasonably doubt that wealth or poverty ripples through many generations, the idea which I hear touted pretty frequently (and is discussed in the article), is that past trauma from war, famine, racism, etc. has a biological mechanism which explains disparities we see today.

As others have pointed out, it's a super convenient conclusion for folks who seek to understand the world in such a way, but at least presently the data just isn't there.

[1] https://en.wikipedia.org/wiki/Transgenerational_trauma

Yes, but the underlying mechanisms behind brains, neurons, cells, DNA etc. aren't going to be so different.

Since human brains and DNA are more complex it is reasonable to suspect the generational transference to be greater than in mice.

Isn’t the article describing in depth how an experiment showed it possible or did I completely misread it? It even explained the mechanisms behind it?

From TFA:

> The study made use of mice’s love of cherries. Typically, when a waft of sweet cherry scent reaches a mouse’s nose, a signal is sent to the nucleus accumbens, causing this pleasure zone to light up and motivate the mouse to scurry around in search of the treat. The scientists exposed a group of mice first to a cherry-like smell and then immediately to a mild electric shock. The mice quickly learned to freeze in anticipation every time they smelled cherries. They had pups, and their pups were left to lead happy lives without electric shocks, though with no access to cherries. The pups grew up and had offspring of their own.

> At this point, the scientists took up the experiment again. Could the acquired association of a shock with the sweet smell possibly have been transmitted to the third generation? It had. The grandpups were highly fearful of and more sensitive to the smell of cherries.

Oh yeah so you want to explain how Epigenetics can transfer the memory of my Grandfathers 17th Birthday Party to my brain?

So, can you give any evidence or even point at a suggestion that inheritable epigenetics can encode inheritable memories?