Can Neuroscience Explain Why Some People Are Total Pushovers?

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Most of us like to think that we’re independent-minded — we tell ourselves we like Adele’s latest album because it suits our taste, not because millions of other people bought it, or that we vote Democrat because we’re so enlightened, not because all our friends vote that way. The reality, of course, is that humans are swayed in all sorts of different ways — some of them quite subtle — by other people’s beliefs and expectations. Our preferences don’t form in a vacuum, but rather in something of a social pressure-cooker.

This has been demonstrated over and over, perhaps most famously in the classic Asch conformity studies from the ‘50s. In those experiments, many participants went along with a blatantly wrong majority judgment about the lengths of different lines — simply, it seems, to fit in. (Although the finding is frequently exaggerated, the basic point about the power of social influence holds true.)

But that doesn’t mean all humans are susceptible to peer pressure in the same way. You only have to look at your own friends and family to know that some people always seem to roll with the crowd, while others are much more independent-minded. What accounts for these differences? A new study in Frontiers in Human Neuroscience led by Dr. Juan Dominguez of Monash University in Melbourne, Australia, offers the first hint that part of the answer may come down to certain neural mechanisms.

In short, the study suggests that people have a network in their brains that is attuned to disagreement with other people. When this network is activated, it makes us feel uncomfortable (we experience “cognitive dissonance,” to use the psychological jargon) and it’s avoiding this state that motivates us to switch our views as much as possible. It appears the network is more sensitive in some people than in others, and that this might account for varying degrees of pushover-ness.

The researchers asked 39 participants, most of them students and 19 of whom were women, to lie in a brain scanner while judging whether 192 factual statements from four topics (biology, history, medicine, and physics) were true or false. The participants were informed that each statement had been made by either a student or a professor, and were told that some of them were known to be false. The statements were deliberately obscure (for example: “Orchid flowers have the most species”), because the researchers didn’t want differences in the participants’ own background knowledge to interfere with their natural disposition to agree or disagree.

Just as they’d hoped, the researchers found there was a wide variation among their participants in their inclination to agree or disagree with the statements — just as in real life, some of them simply had more of a general tendency to go along with what they were told. But against the researchers’ expectations, it didn’t make any difference to participants’ brain activity or response times whether the statements were from a student or professor. The researchers had thought it would be extra awkward to disagree with a professor because of their authority, but they reasoned that perhaps this was balanced out by the awkwardness of disagreeing with a fellow student.

Most intriguing, the researchers found a network of brain regions that was especially active during those rare moments when people who rarely disagreed — that is, those with more pushover-ish tendencies — actually did choose to disagree. This network incorporated several parts of the frontal lobes involved in decision-making, and the anterior insula — a deeper structure that’s involved in the experience of social emotions and bodily sensations, among other things. Collectively, these regions have previously been associated with the experience of cognitive dissonance — the uncomfortable feeling of holding what feel like two contradictory beliefs (i.e.,“My sister is a good person, but she just yelled at a waitress over nothing”).

The researchers interpreted this result to suggest that people who are averse to disagreeing tend to experience worse cognitive dissonance when confronted with views they disagree with (as compared to less agreeable folks), which the researchers believe also comes with a dose of “heightened mental stress and discomfort.” It makes sense that such people agree as much as they can as a way to avoid experiencing this discomfort. Consistent with this account, people who rarely disagreed tended to respond extra slowly on those rare occasions that they did disagree, as if this was a difficult thing for them to do.

Although I really can’t bring myself to openly disagree with the researchers’ interpretations, I should point out that they seem to have indulged in a fair amount of speculation about the meaning of the brain-activity patterns they uncovered. For example, one structure in their cognitive dissonance network, the anterior cingulate cortex, is “one of the most promiscuously excitable structures in the brain,” to quote Sally Satel and Scott Lilienfeld in Brainwashed: The Seductive Appeal of Mindless Neuroscience — meaning it tends to get activated all the time, so it’s hard to know what it’s really doing.

That said, the new results do fit with some earlier findings: For example, a study from 2010 found that teenagers who were more influenced by other people’s ratings of pop songs tended to show more activity in parts of the “cognitive-dissonance” brain network described in the current research, again consistent with the idea that some of us find disagreeing more uncomfortable at a neural level than others do. There’s also a study from 2011 which found that temporarily knocking out parts of this brain network with transcranial magnetic stimulation reduced people’s social conformity.

While three studies aren’t enough to establish anything for certain, it’s intriguing to think that there might be a brain basis for why some people are more sheeplike in their behavior than others. This new neural perspective also suggests you might want to go easy on that acquaintance who is going to a Justin Bieber show next week — maybe her extra-sensitive cognitive-dissonance network made it hard for her to say no to her Belieber friends.

Dr. Christian Jarrett (@Psych_Writer), a Science of Us contributing writer, is editor of the British Psychological Society’s Research Digest blog. His latest book is Great Myths of the Brain.