It is natural to think of our political leaders as either superhumanly clever and benevolent when we agree with them, or else dumb as dishwater and evil when we don’t agree with them. Yet, if one takes our own group-loyalty out of the picture, we can ask the simple question what kind of mental qualities are likely to thrive in our Western political environment.
The political environment we have is highly competitive and combative, with constant media scrutiny and constantly shifting political factions. This gives rise to particular psychological demands and pressures: anyone who can’t keep their story straight or buckles under the relentless psychological pressure put on by the opponents from both within their own political parties and outside, is dead on arrival in politics. Hence the minimum requirement is to be very tough mentally and to have a pretty good memory and ability to keep a straight story. This is of course why so many politicians are lawyers, for the legal profession trains people to be careful with words and to keep a line of argument, irrespective of whether they agree with it or not. So successful politicians certainly need to be in, say, the top 5% of their population in terms of smartness. This tallies well with the estimates of Simonton for the IQ of US president who assigned scores by analysing the intellectual content of their written and spoken works. He puts the average US president at an IQ of 142, with Clinton close to the top, easily 20 points ahead of Bush Junior. This indeed puts even the dumber US presidents in the top 5% of their population.
A completely different pressure that operates in our political environment is that a good politician must sound sincere towards the population, even though the story told changes constantly due to the changes in the political winds. Preferably, he must inspire. Politicians must thus constantly flatter the population, say they will quickly sort out problems they have no actual power to influence, and sell compromises. To be able to sell such dubious stories with a straight face requires a special mental adaptation: either the politician must be a superlative actor who can feign sincerity with ease, or he must truly be sincere even though the story he has to sell makes no real sense and shifts constantly. In the latter case, there is a benefit to being a bit dumb.
Consider what politics would do to someone who truly is sincere and yet reflective enough to see all the elbowing, compromising, back-flips, lies, manipulations, and U-turns that are the normal fare of everyday politics. It would offend his or her senses, make them feel dirty and make them lose their faith in humanity. They simply would be grind down by the relentless pressure towards mediocrity and short-term thinking. Hence politics is not the place for the truly sincere and reflective, certainly not in the modern age. For a similar reason will the meek and the sensitive fail in politics: they are not up to the job of backstabbing when they need to.
I would thus argue you get two types of politicians who thrive in our Western democracies: on the one hand you have people who are really smart and great actors as well, who thus have no problems with telling outright lies and with backstabbing, either for some greater good or their own personal glory. From history, names like Bischmark and Churchill come to mind. The Germans, Italians and French seem to have a history of sophisticated charming actors leading them (like Schmitt and Mitterrand). Many UK prime ministers who survived the ruthless training grounds of Eton would fit in that category too. In America, I would think of people like Clinton (with a reported IQ of 150!) and Nixon. Within the recent Australian context, it would seem to me that Paul Keating and John Howard also fit this bill.
On the other hand, you have those that are sincere because they truly do not see the inconsistencies and selfishness in their own actions and those of others. These would be people with iron self-esteems (egomaniacs?), but who lack the critical reflection needed to recognise their own words and actions for what they are: their sincerity is oriented outwards and not inwards, reminiscent of autism. From history, I would say Thatcher and Bush Junior are examples of this, as are Kevin Rudd and, thinking of Queensland, Peter Beattie. Of the well-known politicians today, Obama seems to somewhat fit this bill too. They have above-average smartness, but they combine it with a kind of blindness for their own bullshit, a combination that allows them to be sincere when they promise the impossible and defend the unbelievable. I believe the term for them is ‘conviction politicians’.
Which kind of politician is better for the population? Hard to tell. I would say in a real emergency (like a world war) you want the sophisticated ones at the helm who are better at reading the situation, but when times are dull a bit of sincere conviction adds spice to life.