Dear founder: An early sign of your startup’s success is when you’re ready to bring in senior leaders or even your first C-suite hires. It’s exciting, but also risky. You need leaders who can make big changes and drive growth, yet also appreciate how far the company has come—cheerleading the progress while leading it into the future without causing too much disruption.

You need leaders who are not only capable of making an impact but also humble enough to recognize that leadership isn’t a one-way street. It’s not just applying what they’ve learned in their past roles—it’s about being open to new learnings and guiding the company without bulldozing what’s already working.

The company I used to work for has been going through a lot of turmoil recently. Most of the C-suite has been replaced twice in a short span. I was there for the first transition, and the biggest thing I noticed was how fast the culture changed—almost a complete 180°—after just a couple of new leaders joined.

That shift reminded me of Nassim Nicholas Taleb’s concept of the minority rule. It means that if a small, determined group insists on doing things a certain way, and the majority is flexible enough to allow it, that small group can end up setting the rules for everyone. Taleb had this idea when he realized that nearly 100% of soda sold in the U.S. is kosher, even though only a tiny percentage of the population requires kosher products.

How does this apply to leadership? When new leaders are brought in and given free rein to do things their way, the rest of the company often has no choice but to adapt. Even if the majority of employees have been around for years and are deeply rooted in the original culture, a small group of senior leaders can shift the entire company’s culture in no time. And sometimes, they don’t even mean to do it—it just happens because they’re used to doing things a certain way.

So, when you hire a leader, you’re not just hiring them—you’re bringing along the culture they come from. If they start hiring people from their previous company at senior levels, you’ll likely see your company culture begin to resemble that of their old organization. If that’s not what you want, it’s probably a good idea to have an honest chat and suggest more diversity in backgrounds when making senior hires.