You might think that a group discussion would temper people’s opinions as they hear different viewpoints and arguments from all sides. However, the opposite is very often true. Group discussions commonly lead to more extreme views.
Most groups are groups for a reason. They have a common purpose or goal, and therefore often have views generally leaning in the same direction to one extent or another. An clear example is a political party, but a less obvious one is the board of directors of a company. The members of the board have a common purpose: the success of the company (or at least – call me a cynic if you will – the personal bonus which may come from short term profits). They are also likely to have been chosen by the CEO, who is not likely to choose people with wildly differing views on how the company should be run.
So, although the board may seem to be a disparate bunch, they are likely to share the same ethos of how business should be conducted, just to different degrees.
It is the same with most groups. Even if they do not appear to be at first, many are self-selecting to be made up of similarly-thinking people. Because of this, any topic likely to be discussed within the group is likely to be an argument about the degree to which a proposition is correct rather than whether it is correct or not.
Let’s take a subject which might be discussed in a left-leaning political party: nationalisation of the railways. There will be some within the party who think that nationalisation absolutely must take place, and others who think that it would be a good idea on balance. There are unlikely to be many who think it is a terrible idea, because if they thought that way they are unlikely to have joined the party in the first place. The average view in that group, then, is going to be that nationalisation is a good idea.
Those with extreme views are always more vocal than those with moderate views because they are usually more certain. Those with moderate views are more considered and nuanced, seeing the value in differing opinions. Anyone who puts forward the idea that private ownership is better (if somehow they found themselves in the party) is bound to get shouted down, and is therefore less likely to voice their opinions.
Because of all this, in the discussion, the loudest and most common voices will be spouting the most extreme views, and the opposite views will not be heard at all. With counter-arguments not being heard, the average person’s opinion is only going to be pushed in one direction – towards the extreme.
Schkade, Sunstein and Hastie found exactly this in their experiments on the subject. They found that, after group discussions, both group verdicts and individual views were more extreme than they had been beforehand. They also found that consensus within the group was increased, but so was the disparity between that group and others.