Sunday, December 16, 2007

Babies Have Values?

According to an article published in the journal Nature (summarized here), babies as young as six months old have a preference for choosing "helpful" toys over "neutral" or "naughty" ones, and even preferred to play with the neutral ones over the naughty ones.

The authors (of the review article) argue that this means that some kind of internal values system is innate:
The choice of nice over naughty follows a school of thought that humans have some innate social abilities, not just those learned from their parents.

I'm inclined to disagree with this statement, on the basis that in six months, the child can learn a lot by watching his or her parents and other prominent caregivers (grandparents, etc) and their social interactions.

Now, if there is something innate about this preference (presumably the babies can only decide if the second toy is helpful or hurtful by empathizing with the first toy), then it is probably localized to the ventromedial prefrontal cortex. This is, incidentally, part of the region destroyed by Phineas Gage's tamping rod accident. The region identified in the image above (borrowed from a different article) shows the ventromedial prefrontal cortex (and part of the medial orbitofrontal as well).

Antonio Damasio and colleagues found, last March, (see summary article here) that individuals with localized damage to the ventromedial prefrontal cortex, which generally processes feelings of empathy and compassion, causes a diminished capacity for social emotions but leaves logical reasoning intact. When asked to resolve hypothetical situations - such as tossing one person from a bridge into the path of an oncoming train, when it would save five other lines - those with the lesions tended to sacrifice one to save fact, they were three times more likely to make such a decision than the intact control group.

This may provide some insight into the ability of the babies to make empathic decisions about which toy to play with. However, at six months, the prefrontal cortex is barely developed. Hell, the somatosensory cortex is only just at its peak of synaptogenesis!

I particularly like this diagram, which I was first introduced to in my first child development class, from Casey et al. (2005):

In the end, I'm not sure what to conclude about this research. I think probably the babies are probably just using information gained by watching their parents, and not really making values-rich decisions.

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