Are We Social Even in the Womb?

Humans are social creatures, or so the psychologists tell us. But when does that social behavior start? Is it biological or cultural? A new study from a team of psychologists examines the behavior of twins in utero, and finds that “by the 14th week of gestation, unborn twins are already directing arm movements at each other, and by the 18th week these ‘social’ gestures have increased to 29 percent of all observed movements. In contrast, the proportion of self-directed actions reduced over the same period.” The “kinetics” of the fetuses’ gestures towards each other was also “longer-lasting and slower to decelerate” than other fetal movements, which indicates that “the fetuses recognise on some level that there is something special about their twin.” Note, however, the tiny sample size (only five sets of twins). [%comments]


Oh, yeah. These comments oughtta be good.

Ian Kemmish

Some species of vivparous shark cannibalise each other in the womb. But I doubt even these researchers would call that "social behaviour". Social behaviour consists of a lot more than merely recognising the existence of another entity.


In the case of twins, their only way "socialising" is with their twin brother. But why? They don't lose much about their opportunity cost. Their opportunity cost of not "socialising" is higher. According to the post, throughout the year the "socialising" (that in fact they call it interactions of the babies) have been increasing, meaning that the twin's socialising increases. Our world in turning into a social world. This kind of studies are probably done with a small marginal cost and is very interesting to know that each generation is turning into a more socialised world and people.


nonsense. life begins at birth. those things in the womb are just globs of protoplasm. there's no ethical reason not to eliminate them, if the woman chooses to do so..


"Longer lasting and slower to decelerate"?! That sounds like they're hitting each other even that young!

Travis L

@Ian but isn't the recognition that other entities have agency the first step (and a prerequisite) to social interaction? I don't think anybody was suggesting that the twins are having high tea, just that they seem to recognize that their twin is a being, and something special compared to the umbilical cord.

Drill-Baby-Drill Drill Team

Early on in gestation there is room for privacy and space to to swing a cat. Late in gestation, as the real estate is limited, the twins have to make accomodations. Embracing in more space efficient than hyperextension and spreadeagle positions.

Also there is a natural grasp reflex in infants that grabs on to anything placed in the palm. Perhaps it was useful as infants clung to the hairy back of their parents as they scurried about the savannah. It is not necessarily a hearty handshake.

Most twins have separate gestational sacs and are diamniotic twin. They are walled off from each other by membranes and cannot firmly embrace or hug. Yes, they have their own rooms.

I think the socialbility is no more or no less in the womb than as witnessed in a newborn. They are grouchy, tired, cold and somewhat angry. And they punch and kick.

Eric M. Jones

Psychologists, Huh...? "Now let's talk about your relationship with your Mother..."

It would be unkind of me to mention that they were also 100% Catholic. And to be a Catholic really means you have to accept that the wine and crackers REALLY (transubstantiation) change into the blood and body of Christ.(who came from Nazareth...which didn't then exist).

Back to reality. Feynman said psychologists (and macroeconomists) were quacks. I'll buy that.


How on earth would you have a control for this experiment? Implant an expanding but inanimate twin substitute in the womb with a singleton and see what happens?



Your response sounds like 'religious conviction' rather than science to me....



I don't think sharks are social creatures.

Drill-Baby-Drill Drill Team

#8 Eric M. Jones
I guess since there are extremist, radical religious and bigoted conservatives, THEN it is predictable that there are also extremist and bigoted ATHEISTS who behave like intolerant stereotyping racists.

Fascists can be religious or atheists. They share intolerance.

Back to Reality, can you really justify that 100% of Psychologist are Catholic. The ones I know are agnostic. And why is being Catholic bandied about like some lower life form?

Fascist intolerance can be of a liberal bent. TOLERANCE MUST BE THE BASIS OF ANY SOCIETY.


My twins were 6 months old (post birth) when they discovered each other. Before then, they would show their recognition of only Mommy and Daddy by cooing in response to our voices and presence. But at 6 months, they discovered that there was another non-parent that they could communicate with. They enjoyed a long call-and-response session from their near-to-each-other cribs.


I read an article just the other day that the offspring of one species of shark EAT EACH OTHER in the womb, with only one surviving.

Maybe these "arm movements" are meant to be lethal blows toward their sibling?

(Of course, I don't believe that, but still we might be filtering such actions through our best ideals.)


I don't think socializing starts in the womb. When a baby is in the womb they are still developing, they don't have the ability to "socialize". Yes, they move. Does it mean they are socializing? No.
I think this is just another way for physchologists to gain publicity and to be another sourcefor this belief that everyone is social and everyone must be. With this 'rage' if I can call it like that, of The Social Network, the recent studies of how social we all are, how important that is, etc., people want to look for more answers and theories to this to gain attention, publicity, and popularity. If you come to think of it..marginal cost? saying something that really has no sense. Marginal benefit? more publicity, popularity, and driving more interest towards the psychologists and what they are finding.


Humans are born biologically with social abilities. Cultural aspects in the human environment change our ways of socializing, but we are all born with these abilities. Twins have an advantage though. Even inside the womb, they have contact with each other and also know that another living creature is next to them. When twins are born socializing is brought up to a new level. Because twins live, breathe and eat and go out everywhere together, these events make it easier for them to socialize and play. They have a partner that is just like them to talk to and play with. Their marginal benefit exceeds their marginal cost whenever they socialize.


This is a very important fact that is being discovered here. We can see how every generation social skills are becoming more and more important to our development. It seems like the most important thing is that the twin actually notices that there is someone there with him/her and that is what they call socializing. It was very smart for this report to come out because for example twins kind of have to eventually "socialize" with their twin, they basically have no choice. The opp. cost of not socializing will be staying alone which is not worth it. They are trapped together so they eventually will recognize each other. So in my opinion, this has nothing to do with the womb. These movements are already present in the kids before they are born, which means that is impossible to stop (among twins.)