April 18, 2009

Social Neuroscience and the Self

The studies from this week’s readings examined the self from a social neuroscience perspective. There were some pretty interesting findings in general, but I think the most important implication of all the studies is that the “self” can be linked back to physical/biological structures. For instance, Gailliot (along with my advisor and their colleagues) observed that acts of self-regulation actually deplete blood glucose levels. And Kelley et al. even found that self-referential (comparing traits to ourselves) thought is related to the deactivation of unique areas of the brain (the medial prefrontal cortex). It’s possible that this area is related to the processing of unique self-knowledge. These findings help remove the self from just being some abstract, theoretical concept, and instead shows how the self is linked to our evolutionary development.

We can also view threats against the self through brain imaging. Eisenberger et al. have shown that social exclusion is linked with activation of the same brain areas that are activated for physical pain. This has significant implications for how important belongingness was for us during our evolutionary development. Our social pain system has co-opted the physical pain system. When we feel exclusion, we really feel pained. It makes sense. Not only is having one pain system suited to deal similarly with physical and social pain more efficient/resourceful, but feeling pained after exclusion is a good way to motivate one to avoid social exclusion. It’s likely that those early humans who were not motivated to avoid exclusion were at a significant survival disadvantage. I think that this also goes in hand with Kurzban’s perspective of the self, in that the self-system evolved in order for us to succeed socially. I wonder then if those self-referential areas (the MPFC) in the brain developed at the same time as when the social pain system started to co-opt the physical pain system.

Another cool finding came from Neiss et al., who were able to link the relationship between self-esteem, executive function and negative affect to genetic influences. Generally, they found that people with low self-esteem had greater negative affect. As well, people with low executive function (self-regulation) had greater negative affect. And they also found that the relationship between self-esteem and affect mediated the self-regulation/affect link. Lastly, genetic factors accounted for a significant portion of variance (38 - 44%) in self-esteem, executive function and negative affect, though the largest contributing factor was due to the non-shared environment. Overall, they concluded that the executive self did not display a genetic or environmental link with negative affect above that shared with self-esteem. This makes sense to me from the sociometer/SCI perspective as well. If we developed our sense of self as a means for succeeding socially, and our self-esteem acts as a guage for our social worth, then negative feelings that come out of an inability to self-regulate should only arise when the regulation issue is connected to social worth (which will be gauged by the self-esteem). So when our self-regulation is low, and we have increased negative affect, it should be because our self-esteem is low too. Very cool.

There is one comment that I have wondered about though. They stated that genetic influences explain 30 – 50 % of the variance in self-esteem usually. I wonder what implications this has for the sociometer hypothesis. If self-esteem is just a guage for our social worth, then I would hypothesize that most of the variance in self-esteem (if not all) would be explained by non-shared environmental factors (i.e., whether we’ve been threatened with exclusion).

Citations for further reading:

Eisenberger, N.I., Liberman, M.D., & Williams, K.D. (2003). Does rejection hurt? An fMRI study of social exclusion. Science, 302, 290 - 292.

Gailliot, M.T., Baumeister, R.F., DeWall, C.N., Maner, J.K., Plant, E.A., Tice, D.M., Brewer, L.E., & Schmeichel, B.J. (2007). Self-control relies on glucose as a limited energy source: Willpower is more than a metaphor. Journal of Personality and Social Psychology, 92, 325-336.

Kelley, W.M., Macrae, C.N., Wyland, C.L., Caglar, S., Inati, S., and Heatherton, T.F. (2003). Finding the self? An event-related fMRI study. Journal of Cognitive Neuroscience.

Neiss, M.B., Stevenson, J., Sedikides, C., Kumashiro, M., Finkel, E., & Rusbult, C.E. (2005). Executive self, self-esteem, and negative affectivity: Relations at the phenotypic and genotypic level. Journal of Personality and Social Psychology, 89, 4, 593– 606.

1 comment:

judy williams said...

thanks, very interesting - I have a background in drug and alcohol use from 25 years ago and am extremely interested in social isolation, self esteem and a lack of belonging. I have been a therapist for 20 odd years and exploring the brain has been paramount in understanding reasons for 'pain relief'.