Skip to content
Lenny's PodcastLenny's Podcast

Using behavioral science to improve your product | Kristen Berman (Irrational Labs)

Kristen Berman is the CEO and co-founder of Irrational Labs, where she helps companies like Google, Airbnb, PayPal, Microsoft, and LinkedIn improve their products and services through behavioral design research. She is also the co-founder of Common Cents Lab, a Duke University initiative dedicated to improving the financial well-being of low- to middle-class Americans. In today’s episode, Kristen shares the 3B Framework of Behavioral Design and uses real-life examples to illustrate what influences behavior change and the common biases that get in the way of building successful products. She also explains how to keep users engaged and how you can implement behavioral design research to drive innovation and growth. Find the full transcript here: https://www.lennyspodcast.com/using-behavioral-science-to-improve-your-product-kristen-berman-irrational-labs/#transcript — Where to find Kristen Berman: • Twitter: https://twitter.com/bermster • LinkedIn: https://www.linkedin.com/in/kristenberman/ • Website: https://irrationallabs.com/ — Where to find Lenny: • Newsletter: https://www.lennysnewsletter.com • Twitter: https://twitter.com/lennysan • LinkedIn: https://www.linkedin.com/in/lennyrachitsky/ — Thank you to our wonderful sponsors for making this episode possible: • Flatfile: https://www.flatfile.com/lenny • Whimsical: https://whimsical.com/lenny • Lenny’s Job Board: https://www.lennysjobs.com/talent — Referenced: Learn more behavioral science: • 3B Behavioral Design Framework https://miro.com/miroverse/3b-behavioral-design-framework/ • Irrational Labs newsletter, with latest BE and behavioral design insights: https://irrationallabs.com/newsletter/ • Join the Behavioral Design Online Bootcamp (use code “Lenny” for 10% off): https://behavioraleconomicsbootcamp.com/ • Get the 3B Framework: https://irrationallabs.com/3bs-download/ • Behavioral Design & Diagnosis Cheat Sheet: https://irrationallabs.com/download-behavioral-design-guide/ • The 16 Critical Cognitive Biases (Plus Key Academic Research): https://irrationallabs.com/blog/cognitive-biases-and-academic-research/ • Behavioral Game Design: 7 Lessons: https://irrationallabs.com/blog/behavioral-game-design-7-lessons-from-behavioral-science-to-help-change-user-behavior/ • Predictably Irrational: The Hidden Forces That Shape Our Decisions:  https://www.amazon.com/Predictably-Irrational-Revised-Expanded-Decisions/dp/0061353248/ • Prolific testing platform: https://www.prolific.co/ • Kristen’s guest post on Lenny’s Newsletter: https://www.lennysnewsletter.com/people/23170097-kristen-berman • Influence: The Psychology of Persuasion: https://www.amazon.com/Influence-New-Expanded-Psychology-Persuasion/dp/0062937650 • The Darwin Economy: Liberty, Competition, and the Common Good: https://www.amazon.com/Darwin-Economy-Liberty-Competition-Common/dp/0691156689/ • The Science of Change podcast: https://podcasts.apple.com/us/podcast/the-science-of-change/id1587407079 • No Stupid Questions podcast: https://freakonomics.com/series/nsq/ • Stream The Rehearsal on HBO Max: https://www.hbo.com/the-rehearsal • Chris York’s website: https://www.chrisyork.co/ - Case studies mentioned:  • Budgeting fintech: https://irrationallabs.com/case-studies/budgeting/ • TikTok: https://irrationallabs.com/case-studies/tiktok-how-behavioral-science-reduced-the-spread-of-misinformation/ • One Medical: https://irrationallabs.com/case-studies/one-medical-case-study/ • Credit Karma: https://irrationallabs.com/case-studies/behavioral-design-credit-karma-money/ • TytoCare: https://irrationallabs.com/case-studies/tytocare-virtual-medical-visits/ • Kiva: https://blogs.scientificamerican.com/mind-guest-blog/the-deadline-made-me-do-it/ • When to Make Your Sign-Up Flow Harder: https://irrationallabs.com/blog/its-not-always-about-making-things-easier-when-to-make-your-sign-up-flow-harder/ — In this episode, we cover: (00:00) What is Irrational Labs, and what do they do? (05:45) What are behavioral economics and behavioral design? (06:50) The fintech budgeting experiment (10:46) What drives behavior change? (11:35) Why increasing friction can sometimes increase conversion (13:51) How to ask the right questions for user engagement (16:09) How Kristen got her start in behavioral economics (18:10) The 3B model of behavior change (20:37) Cognitive barriers (22:02) The importance of building products with immediate benefits to the user (24:20) How exploitation can occur (26:45) How to set customer-friendly incentives (29:15) How Kristen reduced the sharing of misinformation on TikTok (31:58) Tips for researching and solving problems (35:36) The One Medical case study  (38:31) Rules of thumb for improving flow (41:46) What is right-for-wrong? (47:00) How to get started using behavioral design (49:33) The Behavioral Design Bootcamp (52:01) Lightning round! — Production and marketing by https://penname.co/. For inquiries about sponsoring the podcast, email podcast@lennyrachitsky.com.

Kristen BermanguestLenny Rachitskyhost
Oct 1, 202256mWatch on YouTube ↗

At a glance

WHAT IT’S REALLY ABOUT

Designing Products That Nudge Real Behavior Change, Not Just Intentions

  1. Behavioral scientist Kristen Berman explains how to apply behavioral economics to product design, focusing on what people actually do versus what they say. She introduces the "3B" framework—Behavior, Barriers, Benefits—as a practical model teams can use to drive meaningful behavior change. Through case studies from TikTok, One Medical, fintech apps, and onboarding flows, she shows how small, psychology-informed product tweaks can significantly change outcomes. She also addresses the ethics and incentive structures that determine whether these tools help or exploit users.

IDEAS WORTH REMEMBERING

5 ideas

Get uncomfortably specific about the target behavior, not just outcomes.

Teams often aim for abstract goals like “engagement” or “retention”; Berman argues you must define a concrete action (e.g., “two 10-minute workouts with two instructors in 7 days”) before you can effectively design for or measure behavior change.

Map and reduce both logistical and cognitive barriers.

A detailed behavioral diagnosis—step-by-step screenshots plus attached psychologies—reveals where friction actually lives, from form fields and wait times (logistical) to uncertainty, status quo bias, or information aversion (cognitive).

Design for immediate, not just long-term, benefits.

Because people are present-biased, products need near-term rewards—completion satisfaction, social visibility, status, or small incentives—layered on top of long-term benefits like better health, finances, or productivity.

More friction can sometimes increase conversion when it boosts motivation.

Well-designed questions in signup flows (e.g., “What kind of apartment do you want?”) can make users mentally engage with benefits, raising motivation enough to offset added steps and lift completion rates.

User-stated desires often fail in practice without environmental support.

In a fintech case, a heavily requested budgeting feature produced no change in spending because it demanded too much ongoing effort; defaults and simple rules-of-thumb proved more behaviorally realistic levers.

WORDS WORTH SAVING

5 quotes

In order to change behavior, you have to pick a behavior.

Kristen Berman

Any kind of work that we put on the user, we should be skeptical.

Kristen Berman

We are what we measure. It really matters what you measure.

Kristen Berman

Sometimes we say deadlines are a gift.

Kristen Berman

Behavior is contextual. That’s why we are religious about testing.

Kristen Berman

Definition and foundations of behavioral economics and behavioral designThe 3B framework for behavior change (Behavior, Barriers, Benefits)Case studies: TikTok misinformation, One Medical onboarding, fintech budgeting/bank linkingCommon cognitive biases and psychologies affecting product useRight-for-wrong motivations and immediate incentivesEthics, incentives, and the “dark side” of behavioral techniquesPractical process: behavioral diagnosis, experimentation, and available training/resources

High quality AI-generated summary created from speaker-labeled transcript.

Get more out of YouTube videos.

High quality summaries for YouTube videos. Accurate transcripts to search & find moments. Powered by ChatGPT & Claude AI.

Add to Chrome