Leadership Assessment: What makes someone a great leader

What makes someone a great leader? It’s a question organisations have long tried to answer—often through intuition or loosely defined concepts like “presence” or “gravitas.” But recent advances in personality psychology are helping bring more clarity and scientific rigour to this challenge. Leadership assessments, when built on validated personality frameworks, can now offer genuinely predictive insights into leadership potential.

Traditionally, many believed that leadership success was simply a by-product of general job performance. However, emerging research shows that leadership requires distinct competencies—particularly in interpersonal influence, resilience, and emotional regulation—that go beyond the standard markers of job success. These qualities are deeply rooted in personality traits, especially those identified in the Big Five model.

Behavioural assessments are also key, but typically not for the reasons you might think. Most organisations that use behavioural assessments attempt to capture the candidate's leadership style, which is very distinct from leadership ability. Instead, fit to the organisational culture should be considered the priority from a behavioural assessment perspective. Misfit to the organisational culture can be extremely damaging to organisations, and the more senior the hire, the greater the scope for harm. Such senior hires are likely to meet significant resistance from the wider organisation, failing to achieve anything meaningful.

More importantly, recent factor analytic studies suggest that there’s a higher-order personality factor—sometimes referred to as a "General Factor of Personality"—that combines key traits related to emotional intelligence, resilience, and interpersonal skills.

While it’s only moderately related to success in general professional roles, its correlation with leadership effectiveness is significantly stronger.

Leadership assessments aren’t just for hiring decisions—they’re equally valuable for developing existing employees. Behavioural assessments can serve two core purposes: selecting the right people for leadership roles and identifying the strengths and development areas of those already in position.

For instance, consider a leader with a more introverted personality. While extraversion may give a natural edge in social leadership settings, knowing one's introverted tendencies allows for targeted preparation. Rather than attempting to change personality traits—which is neither realistic nor necessary—development plans can focus on areas where challenges are most likely to emerge, such as energy management during social interactions or effective delegation.

Someone with high conscientiousness, for example, might be an excellent strategic planner. Development efforts can help ensure those strengths are leveraged effectively—without becoming crutches or blind spots.

This means organisations now have access to a scientifically validated, singular construct that can be assessed using modern personality questionnaires—especially those designed with leadership in mind. Rather than relying solely on observed behaviour or performance reviews, companies can use these assessments to identify individuals who may not yet be in leadership roles but exhibit the psychological traits that reliably predict leadership success.

In short: leadership potential is measurable, and the tools are already here.

The true power of these assessments lies in their flexibility. When aligned with a company’s specific competency frameworks and values, leadership assessments can provide both broad predictive validity and bespoke relevance. This dual capability enables HR teams to create highly tailored leadership development programmes that are evidence-based, scalable, and aligned with strategic goals.

Ultimately, modern leadership assessments are not only tools for identifying who will succeed—they’re powerful frameworks for helping individuals grow into those roles with purpose, clarity, and support.