Beyond the Deal: Why Culture is the Most Important Thing Leaders Must Get Right

In mergers and acquisitions, leaders spend months perfecting the numbers and crafting airtight strategies. But after the deal is signed, one truth quickly emerges: what determines success isn’t the spreadsheets—it’s the culture.

Successful executives know this instinctively. When two organizations come together, new teams need to succeed quickly. Yet the same lesson applies outside of M&A: culture is the foundation of every high-performing team.

Here’s the playbook for getting it right:

1. Create Psychological Safety
Google’s Project Aristotle found that psychological safety—not IQ, experience, or skill—was the single biggest driver of team success. When people feel safe to share unconventional ideas, admit mistakes, and take risks, performance accelerates. Leaders can model this by asking for feedback on their own behavior and rewarding candor.

2. Co-Create Shared Practices
In a merger I supported recently, success hinged not on integrating systems but on building shared culture. Leadership launched cross-functional “culture pods” that brought people from both organizations together to design new norms—how meetings ran, how decisions got made, and how conflict would be handled. By honoring the best of each legacy culture, they avoided the “us vs. them” dynamic and built something stronger. Within months, engagement scores rose, productivity climbed, and the merged organization began attracting new talent drawn to its clarity and cohesion.

3. Reinforce Culture in Small Moments
Culture isn’t built in policy documents—it’s shaped in everyday interactions. A careless comment can create silence. A single act of humility can open the door to trust. Leaders set the tone in these micro-moments.

The Bottom Line: Deals create opportunities. Culture determines outcomes. Beyond the deal, leaders who invest in culture give their teams—and their organizations—the conditions to thrive.