A few studies indicate that people do a poor job at evaluating both their own skills and the skills of others. A more recent study tries to apply the lessons of those studies to democracy:

Mato Nagel, a sociologist in Germany, recently implemented Dunning and Kruger’s theories by computer-simulating a democratic election. In his mathematical model of the election, he assumed that voters’ own leadership skills were distributed on a bell curve — some were really good leaders, some, really bad, but most were mediocre — and that each voter was incapable of recognizing the leadership skills of a political candidate as being better than his or her own. When such an election was simulated, candidates whose leadership skills were only slightly better than average always won.

Nagel concluded that democracies rarely or never elect the best leaders. Their advantage over dictatorships or other forms of government is merely that they “effectively prevent lower-than-average candidates from becoming leaders.”

Live Science: People Aren’t Smart Enough for Democracy to Flourish, Scientists Say

Nagel’s results are framed as bad news for democracy, but I don’t think these results are so bad. The writer seems assume that the function of democracy should be to determine the best leaders. But even if this were possible is that truly what democracy should do? Karl Popper said in a lecture in 1958:

The question is not ‘Who should rule? or ‘Who is to have power? but ‘How much power should be granted to the government?’ or perhaps more precisely, ‘How can we develop our political institutions in such a manner that even incompetent and dishonest rulers cannot do too much harm?’ In other words, the fundamental problem of political theory is the problem of checks and balances, of institutions by which political power, its arbitrariness and its abuse can be controlled and tamed. […]

For us there are only two types of government: those in which the governed can get rid of their rulers without bloodshed, and those in which the governed can, if at all, get rid of their rulers only by bloodshed. The first of these types of government we call democracy, the second tyranny or dictatorship.

(You can find a longer excerpt at OVO and the full lecture in the collection In Search of a Better World).

Based on this conception of democracy, we should be happy that Nagel’s study indicates that at least the least worthy of leaders will be elected out of office. In other words, people are smart enough for democracy. (Of course, it says nothing to the more central problem of democracies: corruption so deep that there is little point in voting because you’re not even choosing between the lesser of evils, but among puppets of the same evil. Modern democracy seems to have failed, badly, at minimizing the harm done by those in power, and, at least in my view, has slipped into the second type of government described by Popper.)