Imagine a conversation between two people: Preston Power, the CEO of a prestigious corporation, and Alan Awkward, the assistant to the assistant to the regional manager. It wouldn’t take very long to pick up on the difference in social status between these two individuals even if you had no information about who they were. Body language, the tendency to interrupt, volume of speech, and a host of other nonverbal behaviors automatically cue us in to who is the alpha dog in this scenario. While these behaviors are often viewed as personal choices that we can control, Fei Wang and colleagues at the Chinese Academy of Sciences suggest that poor Mr. Awkward may not be at fault for his plight—his neurons may be to blame.
In a recent paper in Science, Wang et al. looked at the strength of excitatory synaptic inputs of specific neurons in the medial prefrontal cortex (mPFC)—a region of the brain associated with social cognition—in a group of mice. They found that more socially dominant mice had stronger excitatory synaptic inputs than low-ranking mice. Moreover, the research group was able to change the social hierarchy by injecting the mice with viruses that either increased or decreased the mPFC’s synaptic efficiency. They suggest that because the mPFC communicates with many other regions of the brain in the chain between social perception and actual behavior, higher synaptic efficiency in this region may not only foster more accurate assessments of what is socially appropriate but may also more effectively signal to other regions of the brain how to act accordingly. This research is provocative in its implication that a “peppercorn-sized” group of neurons could affect social status so dramatically.
Does this mean that some people are just neuronally doomed to be unpopular? Probably not. People are not mice, particularly not in the social domain, where we show an exceedingly higher degree of diversity in group dynamics than our rodent counterparts. Some of our groups are very hierarchical whereas others are very flat, etc., whereas mice show much less variability in their interaction patterns. This research provides valuable insight into a potential neural correlate of social status, but it by no means dictates the determinants of group hierarchies. The set of neurons investigated in this study was chosen because it is the functional analog to regions in the human brain associated with dominance hierarchy-related behaviors; however, analog does not imply perfect one-to-one mapping. In fact, the prefrontal cortex is where we differ most from our other mammalian cousins in terms of both structure and function.
It also seems possible that a sort of feedback loop could be involved rather than a one-way path from neuronal patterns to social standing—that is, engaging in more dominant behaviors such as maintaining good posture and eye contact could alter one’s neurochemistry in the region implicated here, fostering more dominant behavior, and so on—although this is pure speculation. As the study itself shows, the brain is quite plastic and neurochemistry can be changed. Sure, we can’t apply the virus injection method to humans, but it’s certainly plausible that behavioral changes could have similar, if not quite as strong or quick effects. It will be exciting to see whether future research can disentangle these potential pathways.