How can a tiny fly in an airport urinal transform human behavior?

This week, we sit down with Eva van den Broek and Tim den Heijer, authors of The Housefly Effect, to uncover how subtle environmental cues can shape our decisions in powerful and surprising ways.

With Eva’s expertise in behavioral economics and Tim’s background in advertising, they reveal the fascinating impact nudges have on our daily lives. From casino design to placebo crosswalk buttons, the world around us is filled with real-life applications of behavioral science that influence our behavior—even when we know they’re at play.

Join us for practical tips, captivating stories, and thought-provoking insights into how these small interventions can make a big difference in your life. So sit back, relax, and discover the invisible forces of behavioral science all around you.

©2025 Behavioral Grooves

[0:00] Intro - Flies in Urinals?

[6:57] Speed Round with Eva and Tim

[10:58] Exploring the House Fly Effect

[22:07] Why Knowing About Nudges Doesn’t Stop Them

[32:20] Regulating Nudges in Online Casinos

[41:36] Personal Applications of Behavioral Science

[50:37] Desert Island Music

[56:17] Grooving Session: The Bigger Picture of Behavioral Science

©2025 Behavioral Grooves

The Housefly Effect: How Nudge Psychology Steers Your Everyday Behaviour

Illusion of control: Why the world is full of buttons that don’t work

Have You Been Nudged?

David Bowie - Space Oddity

Prince - When Doves Cry

Arooj Aftab - Mehram

Benjamin Britten - Mozart: Symphony No. 25 in G minor, K.183 - 1. Allegro con brio