You’re About to Make a Terrible Mistake! by Olivier Sibony Summary

You're About to Make a Terrible Mistake! explores nine cognitive biases that distort strategic decision-making in business, offering 40 actionable methods to combat them. Drawing on behavioral economics and psychology, Olivier Sibony emphasizes designing organizational processes—not just individual awareness—to reduce errors. The book blends case studies, research, and practical frameworks like "decision hygiene" to help leaders improve choices.

Executives, managers, and decision-makers in business will benefit most, along with anyone interested in behavioral science. It’s ideal for leaders seeking systemic solutions to biases in teams or organizations. Sibony’s clear, research-backed approach also appeals to fans of Daniel Kahneman’s Thinking, Fast and Slow.

Yes—it’s praised for translating complex behavioral science into practical organizational strategies. Reviewers highlight its actionable advice on mitigating biases through structured processes rather than individual willpower. The book’s blend of academic rigor and real-world examples makes it a standout in decision-making literature.

Sibony outlines nine traps, including confirmation bias, overconfidence, and groupthink. He illustrates how these errors manifest in business contexts, such as mergers or investments, and provides tools like "pre-mortem analysis" to anticipate failures before decisions are finalized.

Unlike books focused on individual biases (e.g., Thinking, Fast and Slow), Sibony emphasizes institutional "decision hygiene"—systemic processes to reduce errors. He shifts the lens from personal improvement to organizational redesign, offering concrete methods for teams to leverage collective intelligence.

Decision hygiene refers to structured processes that minimize bias, such as devil’s advocacy, diverse input channels, and scenario planning. Sibony argues these systems are more reliable than training individuals to spot their own cognitive errors.

Examples span industries: failed mergers due to overoptimism, flawed investment decisions from anchoring bias, and product launches derailed by groupthink. These cases demonstrate how biases operate in high-stakes business environments and how to counteract them.

A former McKinsey strategist and HEC Paris professor, Sibony combines 25+ years of consulting experience with academic research. His expertise in behavioral strategy and collaboration with Daniel Kahneman (Noise) informs the book’s rigor and practicality.

Some note that Sibony’s solutions—while effective—require organizational buy-in, which can be challenging to implement. Critics also argue certain methods may slow decision-making, though proponents counter that accuracy justifies the pace.

Yes—principles like encouraging dissent and stress-testing assumptions scale well. Startups can adopt lightweight versions, such as rotating decision roles or using checklists to avoid overlooking risks.

With AI and rapid market shifts amplifying decision complexity, Sibony’s focus on bias-proof systems remains critical. The rise of remote teamwork also heightens the need for structured collaboration to counter fragmented communication.

Yes—Sibony collaborated with Kahneman on Noise and cites his research extensively. He builds on Kahneman’s dual-process theory, applying it to organizational strategy rather than individual cognition.

1. “The best decisions emerge from a process, not a visionary.”
2. “Bias is a team sport—it thrives in groups.”
3. “Decision hygiene isn’t glamorous, but it’s what separates success from disaster.”

These emphasize systemic solutions over charismatic leadership.

It advocates for roles like “bias monitor,” anonymous idea submission, and separating brainstorming from evaluation stages. These methods reduce social pressures and surface diverse viewpoints.

Yes—the book provides templates for pre-mortems, scenario analysis, and red-teaming. Teams can use these to challenge assumptions and stress-test strategies before commitment.