Effective leadership is both art and science. A CEO who instills fear among his or her staff may wield powerful influence in return, but a growing body of research argues that affability may be an even more effective leadership tool.

The debate on what makes a good leader is an ongoing one. The Machiavellian notion that fear trumps love as a results-oriented leadership attribute has tended to prevail over time, but the authors cite studies that suggest warmth is a better conduit of influence than fear. Governance through fear may lead to dysfunction among those being led. Subordinates to a tyrant often eschew creativity and risk taking in favor of mere obedience in an effort to look out for themselves, often at the expense of collaboration and team building. As the authors argue, if a government or company hopes to be effective, then perhaps a gentler approach is warranted.

Although many think that strength and competence are the most important leadership attributes, combining these traits with warmth helps to build trust among employees. This sense of trust, in turn, builds confidence and a willingness to collaborate, share ideas, and innovate. A dictatorial approach to leadership can produce quite the opposite result, which can be destructive to an organization’s endeavors and viability.

Behavior is also a function of physiology. Leaders, regardless of gender, typically show evidence of lower levels of cortisol (an indicator of stress) and higher amounts of testosterone (associated with assertiveness and a willingness to take risks). The right combination of these two hormones can lead to what the authors term “happy warriors”—workers who are able to tackle stressful situations with confidence and emotional stability. Leaders can project warmth and strength through good listening skills, empathy, and body language.

Pundits who analyze organizational behavior in an effort to ascertain the underlying group dynamics that determine an entity’s success or failure should consider not only employees’ technical competence but also the emotional and physiological makeup of the leadership. The latter can have a significant bearing on the work and effectiveness of the former.

Organizational strength is a function of an organization’s culture and its employees’ willingness to embrace it. Effective leadership can make this happen. Ideally, such leadership would itself be a function of competence, strength, and warmth that comes through empathy and trust. Machiavelli got it only half right. Leaders can have it both ways.