Irrational Labs

Kristen Berman's journey into behavioral science began in 2008 when she was a product manager at Intuit working on QuickBooks Online. After reading Dan Ariely's "Predictably Rational," she had an epiphany: "I'm talking to five to ten customers to inform a feature, a product, and try to come up with some insight on human behavior. And yet there's this whole field that studies this, right, that has papers and thinking and studies why we behave the way we do." She realized the product community was missing out on decades of psychological research that could fundamentally improve how products were built.

Berman partnered with Ariely, the famed behavioral economist, and they founded Irrational Labs in 2013. Their early break came when Google became an early adopter of behavioral science for product design. "Google was kind of our first mover in thinking about how important understanding behavioral science was to product and marketing development," Berman explains. Starting with just Dan and Kristen, they hired internal Googlers and expanded their team, eventually working with over 25 teams across the company—from self-driving cars to YouTube—while maintaining an embedded presence for three years. This success validated their approach and gave them credibility to expand beyond Google.

Google's adoption as their flagship customer opened doors to hundreds of companies across industries. Berman notes they now work with "hundreds" of clients including Microsoft, LinkedIn, Intuit, PayPal, Fidelity, and TikTok. Rather than chase every opportunity, they focused on building a repeatable methodology: the "Three B's" framework (Behavior, Barriers, Benefits) that could be applied across different contexts. This framework became their signature offering, with all major clients adopting it as their standard behavioral change model.

One of Berman's most important lessons came from her work with lending platform LendingClub. Asked to increase conversion in their borrower flow with a significant financial incentive (a "five point bump" in conversion), she initially suggested increasingly aggressive tactics until her legal team drew the line—she was approaching predatory lending practices. "I became a predatory lender. I was suggesting things that the legal team was like, no, Kristen, of course, you cannot do that," she recalls. This experience crystallized a critical insight: incentive structure drives behavior, not just the tactics themselves. She learned that companies must measure what truly matters—customer outcomes and long-term value—rather than short-term metrics.

Their work with TikTok demonstrated the power of small, targeted interventions. Tasked with decreasing misinformation spread, they identified a specific behavior to reduce: shares of unverified content. They tested 30+ variations through quantitative research with over 1,000 users, ultimately implementing two simple barriers: an "unverified information" label and a confirmation popup asking "Are you sure?" The result: a 24% reduction in shares of misinformation, and this became one of the first published studies proving this approach worked—later adopted by Facebook and Twitter.

Their work with One Medical shows the power of reducing friction and guiding users. By asking new users health questions during onboarding and recommending a specific provider with limited appointment slots (emphasizing virtual appointments available tomorrow), they increased appointment bookings by 20% without adding complexity. The intervention worked because it made the abstract benefit ("I can get my health questions answered") concrete and immediate.

Irrational Labs has grown to a team of 20 behavioral scientists and expanded their impact to hundreds of companies. Berman emphasizes their rigorous, scientific approach: they conduct literature reviews, form hypotheses, create multiple design variations, and test them quantitatively before implementation. They've moved beyond consulting to productizing their framework, with companies across industries adopting the Three B's model as their internal standard for product development. The most important lesson from their journey is that behavior change happens through predictable patterns—and once you understand the psychology, you can design for it systematically.