"A new study by Bickart and colleagues (2010) examined the relationship between the overall size of the amygdala in a group of 58 volunteers and the number of people in each person's social network. The authors observed a direct correlation between the two: the larger the amygdala, the larger the social network. Why did they expect such a finding? The "social brain hypothesis" (Dunbar, 1998) is cited as providing general evidence in favor of increased brain size in more social animals. However, the major references that motivated the specific hypothesis about the amygdala are book chapters, which seemed rather weak and unscholarly to me..
re we supposed to believe that only one area of the brain is involved in maintaining social networks? I think not. Even within the article, subgroups of participants (i.e., males, all older subjects) showed correlations between hippocampal volume and social network characteristics. This makes intuitive sense, as a better memory might be helpful in keeping track of large numbers of people.
What about cortical regions containing spindle neurons (Nimchinsky et al., 1999), a cell type unique to humans, great apes, humpback whales, elephants and dolphins? Spindle neurons (aka von Economo neurons) are found in the anterior cingulate cortex and frontoinsular cortex. Or how about orbitofrontal cortex, with a volume that correlates with social cognitive competence (Powell et al., 2010)? None of these regions were related to network size."
-More Fascinating Insights Here
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