Performance Is Socially Contagious

I’ve seen strong performers leave organisations for a surprising reason.

Not pay.
Not opportunity.
Not leadership.

Proximity.

Working too long next to people who lower the standard.

Because performance spreads.

Research from Kellogg and Harvard shows that simply sitting within 7.6 metres of a high performer can increase your own output by 10–15%.

Sit near someone disengaged or persistently underperforming and performance can drop by as much as 30%.

That’s called the spillover effect.

And most organisations underestimate how powerful it is.

The Real Cost of Tolerated Underperformance

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In one organisation I worked with, the issue wasn’t compensation.

The A-players were well paid.
The benefits were competitive.
The strategy was clear.

But something else was happening.

Strong performers were quietly compensating for others.

Cleaning up work.
Carrying delivery risk.
Watching standards slip without consequence.

Over time that changes behaviour.

Not dramatically.
Gradually.

Discretionary effort drops.
Ambition becomes quieter.
And eventually, the strongest contributors begin to leave.

Not because they cannot perform.

But because they are tired of performing alone.

Talent Density Matters

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High-performing organisations protect something often called talent density.

Not the presence of a few stars.

But the overall concentration of capable, accountable people within the system.

When most people operate at a high level, standards reinforce each other.

Energy rises.
Ideas improve.
Execution accelerates.

But when underperformance is tolerated for too long, the opposite happens.

Strong performers stop stretching.

They start compensating.

And eventually the system settles around a lower average.

This Isn’t About Elitism

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Especially in Nordic cultures, the idea of protecting excellence can feel uncomfortable.

We value equality.
We value consensus.
We value fairness.

Those are strengths.

But equal worth does not mean equal contribution.

And high-performing environments depend on shared responsibility for standards.

If someone exceptional joins a team where accountability is weak, one of three things tends to happen:

They lower their standards.
They burn out.
Or they leave.

That’s not a talent problem.

It’s a design problem.

Three Ways Leaders Can Use the Spillover Effect

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You don’t need a restructure to improve this dynamic.

But you do need to pay attention to how performance spreads.

1. Map the flow of influence

Where does real collaboration happen?

Are your strongest contributors visible across the organisation, or isolated inside silos?

Proximity shapes behaviour more than policy does.

2. Be intentional about digital proximity

Today influence doesn’t only sit in physical space.

It also spreads through Teams channels, Slack discussions and project forums.

The tone set in those spaces quietly defines what “good” looks like.

3. Protect standards

The fastest way to demotivate a high performer is not to challenge them.

It’s to tolerate persistent underperformance beside them.

You can’t incentivise excellence and protect mediocrity at the same time.

Behaviour follows the environment you design.

The Strategic Question

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If someone exceptional joined your team tomorrow:

Would your culture multiply their impact?

Or dilute it?

Because performance is rarely neutral.

It spreads.

A leadership question

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Before you close this week, ask yourself:

1. Where does performance quietly spread in your organisation?
2. Are your strongest contributors raising the standard around them or compensating for others?
3. If someone exceptional joined tomorrow, would your culture multiply their impact or dilute it?

Thank you for your interest in people.

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