“I inherited an educated, experienced contributor who keeps making careless mistakes and always has excuses,” a leader said to me.

“Has the person been properly trained?”

“Yes—and I’ve personally coached him at least five times.”

When trained individuals continue making avoidable errors, more training rarely solves the problem. At that point, the issue is more about the person’s underlying behavioral patterns.

A useful way to think about personnel development is to sort behaviors into three categories:

• Hard‑wired behaviors — deeply ingrained traits that are extremely difficult to change and tend to resurface under stress.

• Flexible behaviors — habits and skills that may be improved with moderate effort.

• High‑effort behaviors — areas where change is possible but requires sustained structure, accountability, and close follow‑through.

Chronically careless, mistake‑prone contributors seldom transform into consistently reliable performers. Most adults do not dramatically change their core work behaviors, even with repeated coaching. Leaders who try to “remake” people often end up exhausted, frustrated, and no closer to the performance they need.

Effective leaders identify what each contributor naturally does well and assigns work that aligns with those strengths. When leaders place people in roles where their strengths matter most—and their limitations matter least—they perform better, stay engaged longer, and contribute more consistently.