Research on genetics for very small things?

April 16, 2018 7:30 PM

My toddler has a distinctive way of folding his fingers while waving goodbye that I have been told my husband's late grandfather, who baby never met, used to do. Can there really be a genetic cause for such an insignificant thing? If not, what can account for this?

I've heard similar stories from other baby-having friends, about the weird little quirk for this or that which seems to run in families. I find this very interesting. My son went through an earlier phase where he would stick his tongue out when he was focusing on something. His father, paternal grandmother and paternal aunt all did this. And when they saw him do it it, just like with the waving bye bye thing, they went oh ho, look at that that is our thing.

I find this fascinating. I expected genetics for stuff like hair colour, eye colour, allergies and so on (I was not surprised to be handed a sheet called 'your child has eczema!' at his six-month checkup, sorry for that one, kiddo!) But it boggles my mind that there could actually be a gene for sticking out your tongue or how you hold your fingers when you wave goodbye. Has anyone actually researched this? What could account for the 'familial tendency toward waving goodbye in this certain way' if not genetics?

posted by ficbot to Grab Bag (11 answers total)

Best answer: What could account for the 'familial tendency toward waving goodbye in this certain way' if not genetics?

Maybe there is a genetic basis, but as for what it could be besides a genetic cause: confirmation bias, possibly combined with positive reinforcement. Some people move their fingers one way. Some people another way. There are only so many ways to wave one's fingers. Babies and toddlers probably hit on a few different ways in their experimentation.

By coincidence, your baby happened to wave the same way as his great-grandfather (he has eight great-grandparents, no matter how he waved, he probably would have waved like one or more of them). This was noticed (it might not have been remarked upon if he'd waved like the more conventional wavers). So the first answer is coincidence and the possible second step is a bunch of people hamming it up and waving back and saying "look at the way he waves" when he waves that way, which reinforces his waving that way so he continues.

I mean maybe it is genetic, but note that your son gets only 1/8 of his genes from his great-grandfather. And he only gets the particular eighth that is a subset of genes that his father and grandfather have. So do his father and grandfather do the distinctive wave? It could still be a recessive gene if they don't, but at this point you're making a whole lot of assumptions and occam's razor would strongly suggest this is a coincidence.
posted by If only I had a penguin... at 7:48 PM on April 16, 2018 [8 favorites]

People who are blind from birth have facial expression quirks similar to those of sighted family members. Article here.
posted by FencingGal at 7:50 PM on April 16, 2018 [17 favorites]

You might want to look into some of the studies that have been done on separated twins.
posted by BlueJae at 7:54 PM on April 16, 2018 [4 favorites]

Best answer: If you want mechanisms, maybe things like comfort - there could be minute differences in muscle structure or in flexibility or joint sensation that can change how easy a particular gesture is compared to others.

If they're raised by family, there's also always reinforcement to consider - if Mom responds a smidge faster or smiles a smidge more (unconsciously) at a familiar gesture or a familiar movement, that could easily shape a child's patterns.
posted by Lady Li at 11:02 PM on April 16, 2018

Sure it’s genetic, why not. I used to write a list of every book I read with author, title, publication year and carry it in my Filofax (in the paper age). Visited my uncle abroad who I hadn’t seen in years, he had a typed list with the exact same info pinned to a bulletin board over his desk.

The tel3mum constantly expresses exasperation with my exacting pursuit of recipe ingredients and costume replicas... then one day she admitted I got this from her, and recounted her absurd odyssey to get the right tin of oysters in 1968 for a recipe served to a puzzled boyfriend (stay out of this Nigel it’s not about you).
posted by tel3path at 2:09 AM on April 17, 2018 [7 favorites]

My grandpa stuck out his tongue when he was focused on something, and my dad does, and I do, and my kids do. It's not a choice or a considered action; it's a reflex. Last weekend my daughter and I were making tamales for the first time, and a picture of the process shows us both with our tongues out, looking in opposite directions. So there's at least one data point that little throwaway things like that are inherited rather than noticed/reinforced.
posted by AgentRocket at 6:41 AM on April 17, 2018 [1 favorite]

Reincarnation? After all, according to Dirk Gently, once you have eliminated the improbable then whatever remains, however impossible, must be the answer.
posted by runincircles at 6:55 AM on April 17, 2018 [1 favorite]

My two year old son crosses his legs at rest EXACTLY like my father did, who died 10 years ago. It's a pretty unnatural position for a two year old to take but it's always been the most comfortable for him.

I have no doubt it's genetic, though I can't tell you the mechanism. My 4 year old daughter sticks out her tongue when she's concentrating just like I used to do as a child, though there's definitely more of a chance that she's seen me do it at some point, obviously. It still looks innate, she was doing it as a baby too.
posted by lydhre at 7:13 AM on April 17, 2018 [1 favorite]

I too have no doubt these things are genetic. My son whom I did not raise ( unwed mother in the 60s) but am reunited with has the same awful handwriting as me and others in my family, and has mannerisms like his natural father as well. One of my sons I raised resembles and has many mannerisms like my father, so much that his girlfriend could pick out my Dad from a high school team picture because he was sitting and had a facial expression just like my son. Lots of little things are genetic, I am involved in adoption reform and search and often see this in reunited family members.
posted by mermayd at 8:37 AM on April 17, 2018 [2 favorites]

When I was finally in a room with my half-sisters and birth mother, I noticed a moment where two of them laughed at the same time and it sounded just like my laugh. It was very weird. I wasn't raised with them, the higher likelihood is that my laugh should resemble my adopted parents but...well, not exactly!

It also gives me a some peace to see a few character traits in my daughter that seem similar to mine from childhood. I attributed some of these characteristics to a chaotic childhood response but now I have to wonder. Maybe my streak of prickly-jerk is innate?
posted by amanda at 9:12 AM on April 17, 2018

Another bit, my daughter in law and I were walking behind my husband and son, who do not look a lot alike, and noticed that they both walked exactly the same way, with feet pointing out. It was funny.
posted by mermayd at 4:55 AM on April 18, 2018