Although I think there is more to the story, quite insightful thoughts from Richard Posner and Gary Becker on the relationship between intelligence and leadership. A few potential caveats I'd point out very rapidly:
- the examples considered are clearly selected to fit the theory advanced (though it is far from clear that if one considered, say, all -succesful and unsuccesful - political leaders within the last century, from all over the world, not just the USA, the correlation between intelligence and leadership would turn positive)
- "leadership failure" is far from easy to define. What if we are talking about more dimensions to leadership and the leader in question has been highly succesful in some but has made a total fiasco out of others? Would it be sufficient to simply consider whether her last 'leadership spell' coincided with an upturn/downturn in public support? Hence, that last very moment- glory or disgrace- would be the (one and only) proxy?
- I tend to agree that one might not want to have leaders from either the top or bottom percentiles of the (true) IQ distribution, but I also think that the vast majority of these people are very unlikely to ever consider accepting such jobs (for different reasons when comparing the top with the bottom of the IQ distribution, of course). And the example of Einstein refusing the presidency of Israel springs immediately to my mind. Hence, we are probably talking about a truncated "intelligence" distribution from where leaders are sampled, to start with.
- Linked to the previous point, I am rather dubious about placing "cognitive" and "non-cognitive" skills on adverse (or even mutually exclusive) positions for this particular context. If the leader's sampling IQ distribution is indeed truncated (particularly at the top end), I'd conjecture that cognitive and non-cognitive skills can still mix fine in the leader's "intelligence" portfolio without crowding each other out :-).
Below two representative fragments from each of the posts:
Economists have been emphasizing in recent years that that while cognitive abilities of individuals certainly raise their education and earnings, many non-cognitive skills are often more significant. These skills include simple factors like finishing one's work on time, to more complicated ones like good judgments in making decision, or effectiveness at using talents of subordinates. Posner argues convincingly that non-cognitive talents may be of greater importance in determining success at top-level government leadership positions than analytical brilliance and other cognitive skills. (Becker)
What is required at the top levels of government is not brilliance, but managerial skill, which is a different thing, and includes knowing when to defer to the superior knowledge of a more experienced but less mentally agile subordinate. Moreover, so specialized is management as a job that success in managing a business may not translate at all into success in managing a government agency. The firm-specific human capital that a person acquired in a career of management in a business firm may have no value for the management of a government agency, or for that matter a university, a private foundation, or an international organization. Indeed, an experienced manager of a firm may falter and have to be fired if a change in the firm's environment requires a different type of management skill.
Update, 22nd of June '07: It is quite ironic that some people hold the opposite view, ie. "a brainiac for president" (via Greg Mankiw). So just wait now, looking at the approaching USA presidential elections, if Becker and Posner have it right, both Romney and Obama should be out of the election race. And, au contraire, they should be the candidates in the decisive Republican-Democrat face-off if Mankiw's got it right :-). What if I am right? Then all presidential candidates are sampled from a truncated intelligence distribution :-).