"In my view, the main reason for the uneven management sex ratio is our inability to discern between confidence and competence. That is, because we (people in general) commonly misinterpret displays of confidence as a sign of competence, we are fooled into believing that men are better leaders than women. In other words, when it comes to leadership, the only advantage that men have over women (e.g., from Argentina to Norway and the USA to Japan) is the fact that manifestations of hubris -- often masked as charisma or charm -- are commonly mistaken for leadership potential, and that these occur much more frequently in men than in women.
"The paradoxical implication is that the same psychological characteristics that enable male managers to rise to the top of the corporate or political ladder are actually responsible for their downfall. In other words, what it takes to get the job is not just different from, but also the reverse of, what it takes to do the job well. As a result, too many incompetent people are promoted to management jobs, and promoted over more competent people."
-- Tomas Chamorro-Premuzic, "Why Do So Many Incompetent Men Become Leaders?", 2013-08-22