Neuroscience
The idea that humans are social animals has become a truism. Among other things, experts point to the gregarious behaviour of babies - their precocious talents for mimicry and face recognition. What about human behaviour pre-birth? Is that social too? Using what they call the 'experiment of nature' provided by twin fetuses, Umberto Castiello and his team have shown 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 per cent of all observed movements. In contrast, the proportion of self-directed actions reduced over the same period.
Furthermore, the 'kinematics' of the twins' 'caressing' arm movements to each other's head and back were distinct from movements aimed at the uterine wall or at most parts of the their own bodies. That is, the social movements were longer-lasting and slower to decelerate than most other fetal movements, making them similar to the kind of movements fetuses learn to make towards their own eyes. This suggests that the fetuses recognise on some level that there is something special about their twin.
The researchers made their observations using four-dimensional (3-D plus changes over time) ultrasound scans of five women pregnant with twins. These were performed twice for twenty minutes - at the 14th and 18th weeks of gestation.
'The prenatal "social" interactions described in this paper epitomise the congenital propensity for sociality of primates in general and of humans in particular,' the researchers said, 'grounding for the first time such long-held intuition on quantitative empirical results.' Castiello and his colleagues added that further research of this kind could one day reveal the links between social behaviour patterns in the uterus and the later appearance of developmental disorders associated with social impairments.
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Castiello, U., Becchio, C., Zoia, S., Nelini, C., Sartori, L., Blason, L., D'Ottavio, G., Bulgheroni, M., and Gallese, V. (2010). Wired to Be Social: The Ontogeny of Human Interaction. PLoS ONE, 5 (10) DOI: 10.1371/journal.pone.0013199
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Neuroscience
Unborn fetuses demonstrate their sociability after just 14 weeks gestation
Furthermore, the 'kinematics' of the twins' 'caressing' arm movements to each other's head and back were distinct from movements aimed at the uterine wall or at most parts of the their own bodies. That is, the social movements were longer-lasting and slower to decelerate than most other fetal movements, making them similar to the kind of movements fetuses learn to make towards their own eyes. This suggests that the fetuses recognise on some level that there is something special about their twin.
The researchers made their observations using four-dimensional (3-D plus changes over time) ultrasound scans of five women pregnant with twins. These were performed twice for twenty minutes - at the 14th and 18th weeks of gestation.
'The prenatal "social" interactions described in this paper epitomise the congenital propensity for sociality of primates in general and of humans in particular,' the researchers said, 'grounding for the first time such long-held intuition on quantitative empirical results.' Castiello and his colleagues added that further research of this kind could one day reveal the links between social behaviour patterns in the uterus and the later appearance of developmental disorders associated with social impairments.
_________________________________
Castiello, U., Becchio, C., Zoia, S., Nelini, C., Sartori, L., Blason, L., D'Ottavio, G., Bulgheroni, M., and Gallese, V. (2010). Wired to Be Social: The Ontogeny of Human Interaction. PLoS ONE, 5 (10) DOI: 10.1371/journal.pone.0013199Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Twin sisters posing at the annual double take parade in 2007, in Twinsburg, Ohio - the largest annual gathering of twins in the world. (Photo by Rick Gershon/Getty Images).Twins fascinate. Early in life they're often dressed alike, given complementary...
- When Depressed Mothers Give Birth To Thriving Babies
Shelves of evidence show the long-term, adverse consequences for an embryo of having a mother who is stressed or malnourished during pregnancy. For instance, there's medical data showing that underweight newborn babies are more at risk of heart diseases...
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In the second of our on-going series of guest features for psychology students, Dr. Angelica Ronald of London's Institute of Psychiatry describes the use of twin studies in psychology. Psychologists are often trying to control one thing to look at...
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Story on the evolution of vision in humans & primates: Opinion: For Human Eyes Only MICHAEL TOMASELLO New York Times, 1/13/07 "Trying to explain why the whites of human eyes are larger than those of other primates leads to one of the deepest and most...