I have three children - and all are intelligent, beautiful well adjusted kids. 5, 7, and 15.
One thing I made a point of as each was born - I maintained as much physica contact with each immediately after birth. I didnt allow them to leave or be examined without me there, touching them.
I did it not for the posted reasons, but just beacuse it felt right to me.
ALso - I would hum and sing to them a tune while they were still in the womb.
As soon as they came out, I held them and sang and hummed the same tune to them. It immediately calmed them - with my first, she immediately relaxed and stopped crying whil the nurse took her vitals, measurements and pricked her heel.
It was magical.
It probably felt right because it's natural. Newborns pretty much stayed with their mothers 24/7 for all of human history. This is true for chimps ( our closest ancestors ) and even our common ancestor. It's only recently with the push to get women into the workforce where women were encouraged to separate from their newborns so that they could go back to work.
> As soon as they came out, I held them and sang and hummed the same tune to them. It immediately calmed them - with my first, she immediately relaxed and stopped crying whil the nurse took her vitals, measurements and pricked her heel.
The mother's voice also helps premature babies develop. The fetus probably has gotten accustomed to the mother's voice in the womb and associates it with comfort and safety. Perhaps it's an evolutionary relic since many newborn animals are drawn to their mother's voice and vice versa.
This was something I quickly found. I can't seem to find the very article I read however.
Fast forward and we have one 4 and one 7 years old and they are obsessed with reading and would do it every waking hour if we'd let them.
We too would read, sing and hum to my son in-womb. While doing so, we'd occasionally hear a loud click, the source of which we couldn't determine. But after he was born, we found out. He would press his tongue hard against the roof of his mouth then release it with a suction "pop". Was he trying to communicate back to us from the womb? We like to think so!
This is an alveolar click, known as a normal part of certain African languages.
If you've seen the name "!Kung San" around, it is the sound indicated by the "!K".
Instead, articles are full of explanations like this one, leading you to make outlandish conclusions. Hell, even in one of my community outreach events, a farmer came up to me afterwards and said he doesn't want to grow any crops with methylated DNA.
The study does ask for indicators (crying, behaviour, etc.) but with those parameters you can already try to correlate a lot of physical contact vs. less contact.
They are trying to tell whether methylation is worth studying (at all) in the context of more vs. less contact with your child. Personally, for the purposes of raising a child, I don't think these studies say anything at all. It's more important to stop panicking about nonexistent threats that social media wackos will try to convince you of.
Epigenetics is a very interesting field of study and is like a downtuned Lamarckian inheritance all over again. Things like chronic inflammation are still far from well understood. The body is like having 2 000 000 000 years of Wikipedia and all its edit history crammed into one string of DNA letters. And now we learn that apparently metadata (the DNA methylation) is also crammed into the whole thing and even that changes all the time.
By the way, for that matter, what constitutes "affectionate physical contact" quantitatively is not clear to me. I think each child's particular emotional need at any time is really difficult to pinpoint. I had a great childhood and parents, but I think that I always had a sort of angst (maybe competitive angst?) that really can't be said to be anyone's fault. These days if you feel funny and go the psychologist they will probably say: "Don't worry. It's just appropriate affect. If you spend 15 hours a day on Instagram then you are supposed to feel funny."
Anecdotally, there are environmental situations where animals can significantly increase life-expectancy but at the expense of delayed sexual maturity.
It would be interesting, but of course not conclusive, to see if these children experience puberty later and if they also live longer. Perhaps some neglect has some benefit.
Animal models of early postnatal mother–infant interactions have highlighted the importance of tactile contact for biobehavioral outcomes via the modification of DNA methylation (DNAm). The role of normative variation in contact in early human development has yet to be explored. In an effort to translate the animal work on tactile contact to humans, we applied a naturalistic daily diary strategy to assess the link between maternal contact with infants and epigenetic signatures in children 4–5 years later, with respect to multiple levels of child-level factors, including genetic variation and infant distress. We first investigated DNAm at four candidate genes: the glucocorticoid receptor gene, nuclear receptor subfamily 3, group C, member 1 (NR3C1), μ-opioid receptor M1 (OPRM1) and oxytocin receptor (OXTR; related to the neurobiology of social bonds), and brain-derived neurotrophic factor (BDNF; involved in postnatal plasticity). Although no candidate gene DNAm sites significantly associated with early postnatal contact, when we next examined DNAm across the genome, differentially methylated regions were identified between high and low contact groups. Using a different application of epigenomic information, we also quantified epigenetic age, and report that for infants who received low contact from caregivers, greater infant distress was associated with younger epigenetic age. These results suggested that early postnatal contact has lasting associations with child biology.
All cells in our bodies have the same genome. But a hepatozyte and a neuron are very different cells, aren't they? The difference is that cells specialize, and they do so by selectively methylating their genome (not the only mechanism, but an important one), thereby modifying the expression of genes. So a liver has a very different epigenome than the brain of the same person. Now here we're looking at a study of the saliva epigenome, apparently the most important tissue they could come up with.
Then they don't analyze the epigenome in any interesting way. Generally, the more a cell specializes, the fewer genes are active. Expressing this as "more mature" is rather dumb. "More geriatric" would be equally appropriate. Does it not matter at all, which genes are methylated?
So, let's summarize the study properly:
"If you don't touch your child enough, his saliva with age more slowly."
But they don't. They take the (correct, but hardly useful) statement "methylation generally increases with age" and instead say "with maturity" to make it sound impactful.
"consequences on the epigenome" as the article so charmingly puts it.
Indeed such a stupid phrase. Any dynamic activity in the body, every process or change which happens due to dynamic actions during life is technically a consequence on the epigenome, because it requires some cells/organs to change some chemical reactions, produce more of this stuff and less of that stuff - it requires activating some genes and deactivating other genes. You drink tea - it has consequences on the epigenome. You think happy thoughts instead of sad ones - it has consequences on the epigenome... You excercise - it has consequences on the epigenome...
Most likely has to do with confusing cause-and-effect.
It could be just as well that highly methylated babies cry more and could be more demanding or parents with highly methylated babies are themselves less tolerant to crying thus end up handling babies more.
The problem, they way it is being reported, and they way it lines up with pseudo-scientific mumbo-jumbo groupthink makes it stink. That's why it is newsworthy. People want to believe that handling a baby will change their DNA.
Same bullshit like papers like this:
- Scientists Say They’ve Found a Code Beyond Genetics in DNA - https://www.nytimes.com/2006/07/25/science/25dna.html
I haven't read the paper this article is based on, so I can't comment on the study or the reliability of the results.
However, epigentic effects related to the degree of maternal touch have been convincingly demonstrated in naked mole rats in crossover studies. I posted about this research previously. (https://news.ycombinator.com/item?id=18749285)
Contextualizing this single study's result against the much larger, more established evidence from twin studies strongly suggests that one or more of the following is true.
- The results are spurious and won't replicate.
- The results are true, but the association is not causal, and is simply proxying correlation with an upstream factor.
- Lack of touch does lead to methylation in the short-term, but by adulthood there's strong reversion to the mean.
- The methylation has no significant impact on any actual metric that we care about like success, health, personality or wellbeing.
Since identical twins share twice the genetic covariance of fraternal twins, the impact of family environment can be backed out from the respective intra-pair correlation coefficients. In the limit case if genetics played no factor, then fraternal and identical twins should have identical pairwise correlations.
For example suppose pairs of identical twins have 45% pairwise correlation for adult IQ. And say fraternal twins have 25% correlation for the same measure. That would tell us that the population level variance of adult IQ is 40% attributable to genetic heritability, 5% to environmental heritability , and 55% to non-heritable factors (i.e. not genetics and not family environment).
"Twin studies of adult individuals have found a heritability of IQ between 57% and 73% with the most recent studies showing heritability for IQ as high as 80% and 86%.. IQ goes from being weakly correlated with genetics, for children, to being strongly correlated with genetics for late teens and adults. "
Can you think of a reason selection bias could be an issue, thus invalidating twin study cohorts?
A twin study should normalize everything genetically. Ergo epigenetic expression and environment are the only two causal levers. It sounds like you're arguing that parental involvement has a causal impact, which is the point of the studies to a degree.
Perhaps my original question was unclear: is there something the twins do or have done to them that cause a latent selection bias before adoption, thus invalidating the twin studies approach as a whole?
If such an attitude were present in every person, science would not progress at all.
I'm not that long a veteran here, but I think at HN we are more interested in having our minds and ears open and feeling we can comfortably share and discuss articles that make us think, than fostering an attitude like this.
I mean this with respect, whoever you are.
I am a scientist by profession and I have come to believe that the majority of work in this field is wasted because people chase that 5-minute fame. Once you are in the field you can smell the stink a mile away.
It always sounds the same: "A second genetic code discovered", "Touch reflected in the DNA", "Next cure for cancer", "Scientists can edit now genes at high fidelity with CRISPR" all pure bullshit.
it is the premature claim that it changes DNA what is so annoying and misleading.
because once something changes your DNA it suggests that it is there forever (that is why it captures people's imagination)
I don't have the time to dig out the actual study but it looks like  it's originating in Canada (not NIH/USA) based on the publication of the press release.
Original comment of thread doesn't understand how much research is behind this idea (touch linked to higher outcomes long-term). I'd strongly recommend the commenter to read tribler's citation as that's scientific consensus at this point. If you want to read the recent study on DNA affects of touch, then below is that source of research.
1 - https://www.med.ubc.ca/news/holding-infants-or-not-can-leave...
Sadly I have prime view how clickbaity ideas like this one drive most of the motivations behind investigations in life sciences.
It is not just this paper that is bullshit, the whole field of "epigenetics" that this paper is a representation of is bullshit as well - this paper is just one out of the long line.
As I pointed out it there is simply no proof that handling changes DNA. It could just as well handling stimulates the development rate which, in turn, also shows up as another signal.
The lie is not that A and B are present at the same time. The lie is presenting story as if A was caused by B. There is absolutely no evidence for that.
Now hundreds of scientists want a piece of the "cool" story, will jump headfirst into proving how LOVE will reflect in the DNA. No one will care about understanding what the heck is methylation - they will all be chasing baby handling and methylation. That's what I have seen happening and will keep happening thanks to papers like this.
Hence why the main source is published with ~90 subjects studied. Science starts with one paper/experiment and builds from there.
> The lie is not that A and B are present at the same time. The lie is presenting story as if A was caused by B. There is absolutely no evidence for that.
That's not a lie. It's called a hypothesis. It's testable. They've tested it and encourage others to test as well.
Of course, you could say: how dare you, how would you even know, ... I work in this field, the p-hacking, harking (hypothesizing after the results are known) is both pervasive and endemic. they massaged the factors, the genders, the ethnicity, the socioeconomic status etc until the model did something that was publishable.
It simply not possible to accurately correlate these two measures: self-reported minutes of touching a baby with the methylation levels of the DNA of that baby - if you are serious about accounting for all the possible variations across all factors
> Are the neuroendocrine effects of these experiences across the lifespan also mediated by DNA methylation? The answer to this question is not yet known.
So what happened in the following ten (!) years, have we finally figured out whether the effect is mediated by DNA methylation? Nah. Instead, they published another bullshit paper, this time about babies being held...
Ten years is (or rather should be) an eternity in science! The 1st smartphone was barely released back then - how far have gone in technology in this time? Yet we are nowhere closer to have proven or disproven the mechanism. Instead, they would much rather maintain the status quo and publish another bullshit paper.
Until the recent ML-based announcement from Google (and maybe not even with that in hand), protein folding research went nowhere for at least 30 years. So I wouldn't be too critical of a 10 year gap.
> They also asked parents to keep track of how long and how often they gave care to their child that involved physical contact, according to a press release.
If so, to only sample the DNA after the study and not before seems crazy.
There's also evidence healing from trauma can change expression.
What do you mean by persistent state?
There's methyl groups that attach to the DNA. These stop parts of the DNA being read.
There's Histones which wind up your DNA and control how much can be read.
These are used control which parts of DNA are used by which cells. Evey cell has the same Genome, but each cell needs a different program to function, so changing the Gene Expression you get a different kind of cell.
Leaving me with an idle question: has the effect of interaction with plants on child development been studied?