The employee who gets promoted into management is usually the one who was best at the job before the promotion, which is exactly the problem. Being excellent at the individual work and being able to develop other people at that work are different skills, and the transition from one to the other rarely comes with any real preparation. Most new managers learn the role by trial and error, on a live team, with real consequences for the people now reporting to them. The stakes of getting this transition right are larger than most businesses treat them. Gallup's research on the American workforce found that the manager alone accounts for at least 70% of the variance in a team's engagement score: not company policy, not compensation, not even the work itself, but specifically who that team's manager is. A promotion that looks like a reward for one person is, from the team's perspective, a decision that will shape how engaged an entire group of people is for as long as that manager stays in the role.
The manager alone accounts for at least 70% of the variance in a team's engagement score.
What typically goes wrong isn't a lack of intelligence or effort from the new manager. It's that the instincts that made someone a great individual contributor, doing the work themselves, solving the problem directly, being the one people come to for the right answer, actively work against them in a management role. A new manager who can't resist stepping in and doing the task themselves, because it's faster and they're good at it, ends up training their team not to solve problems independently, which creates more work for the manager over time rather than less. The skills that predict success in the new role, like communicating expectations clearly, holding people accountable without becoming punitive, and being genuinely curious about what motivates each person on the team, aren't things most technical or sales-focused promotions have ever required someone to practice.
of the variance in a team's engagement score is explained by one factor: who the manager is. Gallup, "Employees Want a Lot More From Their Managers" →
None of this argues against promoting from within; it argues for treating the promotion as the start of a development process rather than the finish line. A new manager who gets even basic training in the specific behaviors that drive engagement, clear expectations, regular real conversations, recognition tied to actual performance, tends to close the gap with experienced managers faster than one left to figure it out alone. The businesses that get this right tend to build a short, deliberate runway before someone's first day managing others: what decisions they'll now own, what support exists when they're unsure, and what "good" looks like in the new role, defined before they need it rather than discovered under pressure. That small investment up front is far cheaper than the alternative: a talented employee struggling visibly in a role nobody prepared them for, while the team underneath them disengages.
