The Kahneman Chronicles: Lessons from a Fly Lab

Posted by Sameer Thukral, on 26 October 2025

The Kahneman Chronicles #2: Loss Aversion and the Art of Quitting

Daniel Kahneman (1934-2024) was a legendary psychologist who revolutionized our understanding of human decision-making and became known as the “grandfather of behavioral economics.” Awarded the 2002 Nobel Prize in Economics, Kahneman’s groundbreaking research with Amos Tversky revealed systematic biases and mental shortcuts leading people to make irrational choices.

This article series imagines what would transpire when Daniel Kahneman took a sabbatical and worked in a fly lab. Part of “The Kahneman Chronicles: Lessons from a Fly Lab” – A report from our imaginary interdisciplinary fellowship program

Three months into Kahneman’s sabbatical, grad student Tobias stared at yet another failed Western blot, its blank lanes replacing the crisp bands he expected.

“That’s the fourteenth attempt,” Kahneman observed quietly from behind him, notebook in hand.

“I know,” Tobias said. “But I’m so close. I’ve invested eight months to optimise this protocol. I need just one more try with a fresh antibody. Maybe two more.”

Kahneman’s eyebrows rose slightly. “Interesting. Tell me—with what you know now,if you were starting today, would you choose this approach?”

Tobias stared back blankly, silent.

To persist or to quit?

Every lab has them. The experiments that took years. The “almost working” protocols. Projects which drained countless hours, reagents, and emotional energy. And yet, despite mounting evidence suggesting a different path might be wiser, we persist.

“You’re all experiencing two powerful forces,” Kahneman announced at our next lab meeting. “Loss aversion and the sunk cost fallacy. Stopping a project means admitting loss, accepting pain. And we want to avoid pain.”

Loss Aversion: The tendency to prefer avoiding losses over acquiring equivalent gains. Losing $100 feels roughly twice as bad as gaining $100 feels good. The pain of abandoning a project outweighs the potential joy of switching to something promising.

Sunk Cost Fallacy: The tendency to continue investing in something because of past investments, even when cutting losses would be more rational. “I’ve already spent six months on this—I can’t quit now!” But those six months are gone regardless of what you do next.

“Here’s what makes your situation uniquely difficult,” Kahneman explained, drawing on the whiteboard. “Science indeed requires persistence. The breakthroughs do sometimes come on that fifteenth attempt. We celebrate stories of stubborn researchers,who ignored skeptics and proved everyone wrong.”

Postdoc Aisha nodded vigorously. “Exactly! My PI always says ‘science rewards persistence.’ How do we know when we’re being persistent versus just throwing good time after bad?”

Kahneman smiled. “That’s the million-dollar question.Phillip, from your lab, spent eleven months troubleshooting that impossible imaging setup. Everyone told him to quit. But he steadily made incremental improvement—each troubleshooting step revealed new information. New mistakes made and rectified.

And in month twelve, he figured it out. Now it’s the lab’s most cited method paper.”

“But”, he continued, ” Tobias isn’t just continuing because science might work. He’s continuing because admitting loss means admitting a personal failure. His System 1 screams ‘you can’t let all that work be for nothing!'”

This was the uncomfortable truth: there’s no algorithm to tell you whether you’re Phillip or Tobias.

The antidote of six questions

“I wish some GPT will tell you whether to persist or quit,” Kahneman admitted. “But some tools can help you think more clearly about it. Here are six questions I want you to ask about any struggling project.”

He wrote on the whiteboard:

The Fresh Eyes Test: “If a new student joined tomorrow and you described this project, would you assign it to them? Or would you say, ‘Actually, we have better projects available’?”

The Sunk Cost Separator: “Imagine all the time you’ve spent is gone—poof, erased. With what you know NOW, purely about the future, would you invest the next three months in this approach?”. This question removes the weight of past investment. It forces you to evaluate only future value.

The Diminishing Returns Check: “Are your results improving with each iteration, or are you getting the same null results in different fonts?”

The Alternative Opportunity Cost: “What else could you be doing with this time? Not abstract ‘anything else,’ but specifically, what’s the second-best use of your next three months?”. This can help you see what you might be sacrificing.

The Motivation Test:“If this project would definitely fail, and you knew it would fail, would you feel relieved or devastated?”If “relieved,” you have your answer.

The Outside View “What would you tell your best friend if they described this exact situation to you?” We’re terrible at evaluating our own situations but remarkably clear-sighted about others’ problems. Use that. That’s the purpose of lab meetings, conferences, poster presentations and talks.

Conscious pivoting

“Pivoting doesn’t mean your previous work was wasted. They’re only wasted if you learn nothing. If it helps, take a moment to say farewell and grieve over the failure, but then decide to stop”

Yan spoke up. “So how do I know if I quit too early? What if I abandon something that would have worked?”

“You don’t know, no one knows,” Kahneman said bluntly. “That’s the brutal reality. You’re making decisions under uncertainty. The goal isn’t to eliminate uncertainty. It’s to make the decision consciously, based on forward-looking analysis rather than backward-looking regret aversion.”

A month later

Tobias came to Kahneman with a decision. “I’m stopping the Western blots. But I’m not abandoning the question—I’m switching to a mass spec approach. It’ll take time to learn, but the core science is still sound.”

“How do you feel?” Kahneman asked.

“Honestly? Relieved. And excited. Which tells me something.”

Across the lab, grad student Aisha had reached the opposite conclusion about her struggling project. “I’m continuing,” she announced. “But I’m setting a deadline: three more months with weekly milestones. If I’m not seeing incremental progress, I pivot.”

Kahneman nodded approvingly. “Notice what you both did? You made conscious, analytical decisions. You acknowledged the sunk costs but didn’t let them drive your choice. You looked forward, not backward. Whether your projects succeed or fail, you’re making better decisions.”

Some successful scientists succeeded because they persisted. Others succeeded because they quit and tried something else. Both paths lead to success stories. Both paths lead to failures. Sometimes keep going and sometimes, pivot. But do so consciously.

Have you experienced similar pain in letting go of projects or ideas? Do share in the comments.
What else did the Prof. Kahneman advise us on? Stay tuned for the next article in the series.

Sameer Thukral is a post doc in the lab of Yu-Chiun Wang at RIKEN-BDR, Kobe, Japan, where he loves discussing science in the healthy and respectful lab environment. He is a developmental biologist with a focus on mechanics of yolk-blastoderm interactions. He is also the co-founder of BDR-Launchpad, a post-doc network for supporting ECRs with the hidden curriculum of science.

The observations made here are his own and do not reflect the opinions of the employer. This article was written by Sameer Thukral, with formatting, structuring and framing support of Claude AI.

Part 1 of Kahneman Chronicles