Partisan Irrationality and the Credibility Index
By Crispin Sartwell
A true man thinks not what his listeners are feeling, but what he is saying. (Laws of Ethelred ["The Unready"], 10th century)
Some years ago, our team here at the National Institutes for Logic carried out a groundbreaking piece of research. We demonstrated beyond quibble that those who very frequently agree with the consensus of people on their own side of the political spectrum with regard to factual matters are as rational as sleep-deprived toddlers. One of the most remarkable features of this bold undertaking, which occupied some twenty-seven years and consumed tens of millions of dollars in grants and dozens of toddlers, is that we proved decisively what was completely obvious to begin with.
This is a particularly appropriate time to deploy our breakthrough, which we term the Credibility Index (CI). It is a useful tool which will enable you to assess objectively the extent to which anyone, including yourself, is connected to reality.
A few months ago, it was common for Trump supporters to question the legitimacy of the American electoral process, whereas his opponents were outraged by the very idea. In that innocent time, leftists decried and protested the terrible violence in some inner cities; now they celebrate these places as safe and fully functional communities. Then, conservatives seemed to regard it as unpatriotic to doubt our intelligence agencies; they have discovered the history of its lies and failures.
Obviously, you should doubt the sincerity or rationality of people who, in a mass, contradict their own apparently passionate beliefs for the purpose of vilifying their opponents. But there was no point in listening to anyone in the mainstream of either of these political factions - left or right, Democrat or Republican - to begin with. This can be proven.
Suppose we are conducting a poll about whether the intelligence report on the Russian electoral hack is plausible. And suppose that half the people expressing an opinion say it is, and half say it isn't. And suppose as well that the publicly available evidence on this is murky and split. The overall 50/50 split of opinion is more or less what we'd expect given the state of the evidence. So far, so rational.
However, as we pollsters dig down into the data, we discover something bizarre: all the tall people believe that the report is plausible, and all the short people believe it is not. This strikes us as unaccountable, because height has no bearing on access to the relevant information. We'd expect both groups to be split. We must conclude that at least half the people on both sides are forming their opinions irrationally, that their height, rather than the evidence, is correlated with or is determining their opinions.
Being on the left or right in this case is exactly like being over or under 5'8": evidentially irrelevant. What counts is specific sources and methods, or the real credibility of people who are in a position to know. That you celebrate free enterprise or revile inequality is neither here nor there. If all the political positions of the Democrats were true, this would tend neither to establish nor to demolish the truth of the intelligence report. Your place on the political spectrum is entirely irrelevant with regard to the evidence, on this and many other matters.
Every time tall people agree as a group on a controversial claim (that the American electoral system is illegitimate, for example), it becomes more obvious that they are not responding to the evidence and that they ought to have little credibility. That they believe it is not any sort of indication that it's true. It's just their height talking.
And that is obviously the situation with party spokespeople, political consultants on one side and the other, partisan pundits, and indeed with most Americans in this bubbly moment: every time they agree with the consensus of people on their own side, where the evidence is split and group membership irrelevant to it, their credibility is multiplied downward. If it's 50% after one such foray, their CI is .5 out of a possible 1. After two, it's .25, and so on. Let them agree with their group on seven such matters in a row, and their overall credibility is about .004. Science tells us that we'd be better off listening to untreated schizophrenics. And if you yourself agreed with your own side the last seven times out, we here at the National Institutes for Logic urge you to take some quiet time alone and reflect.
One's political position is entirely irrelevant to questions like the severity of climate change, whether gun control reduces violence, or the conditions in John Lewis's congressional district. But antecedent group affiliation largely determines people's opinions on these matters. If you're wondering whom to believe, find people whose affiliations do not at all predict their factual beliefs. Those are the only people in this situation with a decent CI, the only people with an objective claim to be regarded as credible. One wonders whether there are any such people.
Political polarization, in short, has turned Americans into idiots, with regard to the question of whom to believe, and with regard to what the world is actually like. Political partisans have replaced reality with one another, in an infinite round of epistemic backslapping in which they congratulate people who agree with them on their own sagacity. They're so busy bonding that they forget that there's an actual world.
Now that would merely be amusing or even sort of sweet if it were a matter of people coalescing like little raindrops into placid collective pools. Sadly, however, these groups are formed up as much by hatred and exclusion of the other as by their yearning for internal unity. Abandoning the world for your group turns out to be a good way to break a nation in two.
Crispin Sartwell teaches philosophy at Dickinson College in Carlisle, PA. Follow him on Twitter @crispinsartwell.
If you don't quite get what I'm doing here, (a) I'll keep trying, (b) this might help. Also may be of assistance if you are thinking of apparently obvious objections.
