Mark Horstman quotes "The Effective Executive" by Peter "MBO" Drucker — there is no such thing as the only viable manager personality type.
…there are extroverts and aloof, retiring types, some even morbidly shy. Some are fat and some are lean. Some are worriers, and some are relaxed. Some drink quite heavily, others are total abstainers. Some are of great charm and warmth, some have no more personality than a frozen mackerel. There are some others would consider a “leader.” But equally there are colorless ones. Some are scholars and serious students, others almost unlettered. Some have broad interests, others know nothing but their own narrow areas. Some are self-centered, even selfish. But there are also those who are generous of heart and mind. There are those who live for their work and others whose main interests lie outside — in community work, church, Chinese poetry, or in modern music. Some use logic and analysis, and others use perception and intuition. There are those who make decisions easily, and those who suffer agonies doing so.
…effectiveness is a habit, a complex of practices. And practices can be learned.