Succession Effect: How Consecutive Women Prime Ministers Shifted Leadership Style in New Zealand

Given the global pattern that women leaders are often pressured to display masculinity to be seen as effective, this study asks whether those expectations—and the leadership styles they promote—can change over time.

🔎 How Leadership Was Measured and Compared

• Introduces the Ferrous Scale, a new methodological tool designed to quantify stereotypically masculine leadership style.
• Applies the Ferrous Scale to the three female prime ministers of New Zealand to track changes in leadership style across successive women leaders.
• Supplements scale measurements with in-depth interviews of all three women leaders and evaluates a set of competing hypotheses about causal mechanisms.

📊 Key Findings

• Ferrous scores decline with each successive female prime minister, indicating a measurable reduction in stereotypically masculine leadership traits over time.
• Interview evidence and hypothesis testing point to a "Succession Effect": a sequence of female prime ministers—rather than broad societal gender progressiveness or partisan affiliation—appears to be the key condition that loosened the association between executive office and masculinity.
• The results indicate that repeated female incumbency can alter expectations about what an executive leader looks and acts like.

💡 Why It Matters

These findings reshape understanding of gendered leadership norms by showing that change can be driven by patterns of officeholding itself. For scholars and practitioners interested in representation and executive politics, the study suggests that sustained female presence in top offices may be a distinct pathway for loosening gendered expectations about leadership style.