From Accidental Manager to Accidental Diminisher: The Hidden Cost of Untrained Leadership
In today’s fast-paced, ever-evolving workplaces, effective leadership isn't optional—it’s essential. Yet research from CMI* shows a staggering 82% of people promoted into management roles have never received formal training in how to lead. These so-called “accidental managers” are skilled professionals—engineers, lawyers, analysts, consultants—who find themselves leading teams without the guidance, tools, or mindset needed to lead effectively.
They step in with good intentions. But without training or support, many unintentionally become something more harmful: accidental diminishers.
The Accidental Diminisher Effect
According to Liz Wiseman, author of Multipliers, accidental diminishers are leaders who unintentionally stifle the intelligence and capability of their teams—even when they genuinely care. They micromanage, over-direct, or rescue their team too quickly. They might be overly helpful, constantly jumping in to solve problems, or unknowingly create dependency by being the go-to person for every decision.
They don’t mean to diminish others—but the impact is real.
Wiseman’s research reveals that "diminishers" get only about 50% of their team’s intelligence and capability, while "multipliers"—leaders who amplify others—get closer to 100%. That’s not just a nice idea; it’s a massive difference in performance, engagement, and innovation.
What’s the Cost of Getting It Wrong?
The consequences of accidental diminishment are both human and commercial:
Burnout and disengagement: Talented team members feel overlooked, underutilized, or micromanaged.
Missed opportunities: Innovation and problem-solving slow down when only one person’s voice (the manager’s) dominates.
Leadership bottlenecks: Teams become dependent on their manager for every decision, slowing momentum.
Attrition: High performers often leave not because of the work—but because of how they’re managed.
In an economy where adaptability and creativity are currency, leaders who suppress team potential—accidentally or not—cost businesses dearly.
What Can Be Done?
Here’s the good news: this isn’t about blame—it’s about awareness, and better yet, growth
Becoming a great leader isn’t a trait you’re born with—it’s a skill you develop. And modern, self-aware leaders are already positioned to evolve from accidental diminishers into intentional multipliers.
Here’s how:
Invest in real leadership development
Formal training matters. Research shows that trained managers are more likely to:
Trust their teams
Champion change
Address poor behaviour early
Create psychological safety
Adopt a multiplier mindset
Ask yourself: Am I making space for others to contribute? Am I leading with curiosity over control? Learn how to unlock the intelligence of those around you, rather than doing the thinking for them.Build self-awareness as a core competency
Emotional intelligence, reflection, and feedback loops are not soft skills—they are core leadership skills. Great leaders show humility and courage—key to developing awareness and exposing blind spots.Create a culture of continuous learning
The best leaders aren’t know-it-alls. They’re learn-it-alls. Create environments where learning, experimentation, and personal growth are normalized—starting with yourself.
From Accidental to Intentional
If you’ve found yourself leading without a roadmap, you’re not alone—and you’re not stuck. The shift from accidental manager to intentional leader begins with awareness and continues with deliberate action.
You can become the kind of leader who multiplies talent, unlocks potential, and leaves a legacy—not just of performance, but of people who thrive under your leadership.
👉Get in touch if you are curious to explore how coaching can support your leadership journey.
* Chartered Management Institute and YouGov Research: Taking Responsibility: Why UK plc Needs Better Managers (2023)