By Dr. Matthew Jones, PsyD, Licensed Psychologist and cofounder coach
Most founders who end up struggling with their cofounder did try to vet each other, often more carefully than most teams ever do. As a Licensed Psychologist who has worked with hundreds of founding teams, I’ve learned that answering the questions isn’t the same as knowing how to test a cofounder before you commit, and the gap between the two is where a lot of partnerships break.
What follows is a Q&A on this topic. I hope you find it useful.
Aren’t the cofounder dating questions enough?
They’re a good start, but they aren’t enough on their own. A lot of cofounders go through Gloria Lin’s 50 questions, published by First Round Review, and they offer a lot of value. You discuss commitment, equity, sacrifice, values and how you’ll operate, and plenty of teams never have those conversations at all. So if you’ve discussed them intentionally, you’re ahead of the curve. But even if you answer every single question in good faith, you still haven’t been tested. That’s the difference between knowing the answer and actually living it. There are two reasons the answers are less helpful than lived experience: most teams never get specific enough, and you’re answering as the person you are on a good day.
Why didn’t our answers reveal that we wanted different things?
Usually because you never got specific enough. Two cofounders I recently worked with both left a company where they’d been colleagues to start a new venture together. They went through the questions, then agreed to a RACI chart. The technical cofounder agreed to just be informed on areas outside his domain. What he actually wanted was to be consulted, because to him, that’s what a cofounder is. In the CEO’s view, the cofounder title was basically a bump in equity. What mattered far more was executive power, separate domain ownership and moving really fast in parallel. The CTO wanted domain ownership too, but he expected that as a cofounder he’d have visibility and influence in the other domains as well, at least until the company scaled. They never clarified what it meant to be an executive versus a cofounder, and they never pushed to define “informed” or “consulted.” That led to massive incompatibilities in the zero-to-one phase. My recommendation is simple: get more specific.
How will my cofounder act when things get hard?
You can’t know that from their answers, because they’re answering as the person they are on a good day. There are aspirational values and lived values. Aspirational values are the ones you’d name if someone asked you what your values are. Lived values are what a third party would see if they watched your behavior. The fundamental insight of psychoanalysis is that we are of many different minds, and sometimes it’s not the conscious voice that wins. Entrepreneurship invites regression. You’re going to be exhausted, sick and under pressure. It’s easy to say you’ll be calm during a disagreement and another thing to be in it, reckoning with your own physiological activation and frustration.
In 1995, Benjamin Karney and Thomas Bradbury reviewed 115 long-term studies covering more than 45,000 marriages and developed the vulnerability-stress-adaptation model. Whether a marriage lasts depends on three things working together: each person’s enduring vulnerabilities (their personality, their family history, the way they learned to cope), the amount of stress the couple faces, and how they engage with each other under that stress. A pair can look solid in calm conditions and come apart under pressure. That absolutely applies to cofounders. The 50 questions measure you in calm conditions. They can’t measure how the two of you will handle stress once it arrives, and unfortunately, you often find out who your cofounder really is with money, a team and your reputation on the line.
What happens to the issues we didn’t resolve before starting?
They come back as the company grows, stacked on top of new problems. That includes the topics you never got to and the answers that felt resolved but weren’t specific. Next to building the product, getting customers and raising capital, those leftover topics don’t feel urgent. So the story becomes “we’ll get to it once the demo works,” then “once we have more customers,” and that day never comes.
What I often see as a cofounder coach is that the rate at which the company grows exceeds the rate at which the partnership grows. That gap creates relational debt you have to pay down to keep pace as the company scales. It helps to think in developmental stages: whatever you skip early stays unresolved and shapes everything after. Say you split equity evenly to show good faith and went to build the product. As the business matures, you realize you’re committing far more and delivering more value. Now, right as you decide who’ll be the face of the fundraise and own the investor relationships, which brings status and power into the room, you also have to reopen equity. That’s two difficult conversations at once, in the middle of a raise.
What answers should worry me when vetting a cofounder?
Listen for three things: extreme answers, big gaps between your perspectives, and rigidity. Any of them can be an early sign of problems to come, and I’ve worked with cofounders where all three showed up. One founder said he was only willing to leave his company if his partner would give up everything in his life, including his sleep, his health and his marriage, because of how much reputational risk he was facing. That’s an extreme answer. His cofounder said yes, and it was true at the time. Then his wife became very sick, and his priorities shifted. That opened a big gap: he was no longer willing to give the company everything, and the first founder saw it as a breach of contract. Then came the rigidity. The second founder hoped they could renegotiate the equity or adjust compensation, but the first founder wasn’t willing to, and they parted ways.
How do I test a cofounder before I commit?
Do a working trial long enough to say yes to two things: we’re aligned on what we’re building, and I know how you show up under stress. Think in milestones, not a fixed number of weeks. Ideally that’s multiple months, depending on whether you’re full-time, venture-backed and racing to market.
On an objective level, you want to be able to say that you understand where you want to take the business, including your one-, three- and five-year plan, how you see the market and whether you’re building venture-backed or bootstrapped. You’re seeking similar financial outcomes, ideally with similar runways, and taking on similar reputational, career and financial risk. You agree on how much time and sacrifice each of you will give, you’re realistic about how hard this will be, and you’re flexible when that changes.
On an interpersonal level, you want to be able to say that you’ve seen how your cofounder responds when things get hard and you still enjoy working with them, that you can give and receive feedback both ways, and that you’ve had an actual disagreement and repaired it. That’s psychological safety. It isn’t built in the honeymoon period. It’s built through cycles of rupture and repair, and how you handle a hard conversation gives you far more data than how many of your answers matched. You want to say yes to both based on lived experience and explicit communication, rather than idealization because it feels good and feels urgent.
Then write it down in a cofounder agreement. I use the Partnership Term Sheet from my book, The Cofounder Effect, a document where cofounders spell out their roles, responsibilities, decision rights and commitments, how they’ll repair after conflict, and how they’ll update the agreement as the partnership and the business grow. This is the work of cofounder coaching.
If you skip the test, you still find out who your cofounder is under pressure. You just find out after you’ve raised money, hired a team and split the company. Once you’re working together, the Cofounder Diagnostic at https://cofounderdiagnostics.com shows you what you don’t yet know about each other and which level of your partnership to work on first.
Author Bio
Dr. Matthew Jones is a licensed psychologist and cofounder coach, founder of Cofounder Clarity, and cofounder of the Institute for Founder Dynamics (founderdynamics.org), a nonprofit advancing the science and standards of cofounder partnerships. He is the author of The Cofounder Effect and has worked with hundreds of founding teams. Watch his videos at youtube.com/@CofounderClarity.
The cofounder coaching guide (https://cofounderclarity.com/cofounder-coaching): for founders who’ve already committed and are now seeing the gaps this post describes.