Influencing: Our minds distinguish between various social influences

When people change their opinion after they have received additional information from another person, this is an example of informational social influence. But when people revise their views because they want to be socially accepted, researchers refer to normative social influences. Previously, it was uncertain which neural mechanisms underlie these two situations.  

What the researchers say: “This question is all the more relevant in today’s world of social media and the manipulation of opinions, as many people rely on the opinions of others to form their own view,” said the study’s lead author.

The study has been published in PLOS Biology.

“We were able to show that our brain solves social conflicts – that is, differences of opinion – via the same neural machinery that it uses to solve its own internal, subjective conflicts,” summarizes the lead author. “A specific region of the brain takes two factors into account: how confident we are in our opinion and how polite we are obliged to be toward others.”

In their study, the researchers used a computer-based game. Participants in the experiment had to try and remember the position of a dot displayed on a screen. They gave confidence values for their answers. However, they were allowed to revise their guesses after they had seen the answer of a computer or of a virtual ‘partner’ to whom they had been introduced before the experiment. In reality all answers were provided by computers.

The team tracked the brain activity of all test subjects during the game using functional magnetic resonance imaging (fMRI). This non-invasive method allows areas of the brain with high activity – that is to say, with high oxygen consumption – to be displayed with high spatial resolution.

The study showed that people tended to adjust their answers when their confidence was low, irrespective of whether they thought their partner was human or not. This informational influence was controlled by activity in the dorsal anterior cingulate cortex (dACC) of the brain, a region of the cerebral cortex.

Test subjects also exhibited more conformity toward other opinions if they received confirmation from their communication partner. This normative influence arose only when they believed that their partners were human, as did the correlation with dACC activity. Moreover, the normative influence was associated with stronger functional connections between the dACC and other social processing regions of the brain. This was not the case for the informational influence.

As part of the study, the researchers also wanted to know what their results meant for AI applications, which are increasingly being used in all kinds of areas. “We established that the human brain only feels the need for politeness when it’s interacting with other people and not with a purportedly artificial (albeit intelligent) agent,” said the researchers.

So, what? This is an important study in the realm of human decision-making. It reinforces what Alicia and I have been saying for many years now: that the main influence in almost any decision is the need to please other people.

We disagree with the researchers in that we do not think it is a question of being polite. Rather it’s the fundamental human drive to strengthen existing supportive relationships or to gain new ones. If two people agree on something—regardless of whether it’s right or wrong, or even if neither actually believe it to be the case—they establish a commonality. Commonalities are the basis of both belonging and trust.