The Power of One: How Negativity Shifts a Team

We’ve all been in that meeting — the one where a single person alters the tone for the entire group.Enter Negative Nellie: disengaged, dismissive, and clearly uninterested in contributing.

At first, we navigate around them, trying to minimize their impact or simply ignore the undercurrent of negativity.

But here’s the catch — our brains are wired to attune to others. We unconsciously acclimate to the emotional tone of the group, and before long, we surrender. Enthusiasm fades, focus drifts, and staying positive becomes a battle you can’t win.

It’s almost as if our minds seek the collective behavioral average. Remember high school? One bad grade could tank your GPA — the same thing happens to team morale.

The Science Behind It

Researcher Will Felps, PhD, studied this phenomenon by planting a “disrupter” into study groups. This person rotated through three roles — the Jerk, the Downer, and the Slacker — to observe how each personality influenced the team.

The results were clear: one person can singlehandedly shift a high-performing team toward dysfunction, reducing effectiveness by 30–40%, lowering morale, and even causing team collapse.

The good news? Not all hope is lost.

Felps found an outlier group — one that resisted the negativity. The difference? A single participant who quietly, confidently counteracted the toxic behavior. Without aggression or defensiveness, this person created psychological safety through inclusive comments, positive feedback, and open body language.

One person can destroy a team’s energy — but one person can also restore it.

The Leadership Imperative

As a leader, it’s your responsibility to minimize disrupters and create accountability for behavior. Early identification and intervention are critical. Negativity has a disproportionately asymmetrical impact — one person’s pessimism can outweigh the optimism of several others.

Negativity spreads faster, lasts longer, and drains collective energy more than positivity can replenish it.

What’s tolerated over time becomes the norm. Don’t be naïve to the erosion happening underneath. Teams may appear to successfully navigate toxic behavior, but it only takes one enticing job offer for the entire structure to collapse.

Loyalty and commitment require more than a paycheck. People want to feel safe, seen, and supported.When you tolerate negativity, you send the opposite message: we value performance over people.

My Challenge to You:

Objectively look at your team and honestly assess: What level of negativity or disengagement are you currently tolerating?

It shows up in many forms — subtle and not-so-subtle: 

• Lateness to meetings

• Multitasking while others speak

• Overtalking or derailing discussions

• An aggressive or dismissive tone

Now ask yourself:What’s keeping you from holding this person accountable?

A common justification sounds like this: 

“They’re a top producer. We can’t afford to lose them.”

But here’s the hard truth — by tolerating their behavior, you’re already losing something: trust, morale, and alignment.

Find clarity in your organization’s values.Are your actions — or your inaction — truly aligned with them?

Finally, socialize the need for alignment across your team. Set clear expectations, communicate supported consequences, and model the courage to protect your culture.

Culture isn’t built by the loudest voice in the room —it’s shaped by the leader who has the courage to defend it.