How to Make Better Decisions: The Evidence-Based Guide

This guide synthesises the current evidence on decision making and cognitive bias into clear, practical steps you can implement immediately.

What the Research Shows

The evidence base here is robust. Small, consistent changes compound dramatically — and the fundamentals matter more than any single intervention.

Key Principles

• System 1 thinking (fast, intuitive) is prone to bias; System 2 (slow, deliberate) is cognitively expensive.
• Pre-mortem analysis (imagining the decision failed and asking why) is the most effective bias-reduction technique.
• Confirmation bias — seeking evidence that confirms our existing belief — is the most pervasive and costly bias.
• The "10-10-10 rule": how will you feel about this decision in 10 minutes, 10 months, and 10 years?
• Reversibility matters: make irreversible decisions slowly and carefully; reversible ones quickly.
• Decision fatigue: the more decisions you make in a day, the lower the quality — batch non-urgent decisions.

Getting Started

Pick one principle and apply it consistently for 14 days before adding another. Sequencing habits dramatically improves long-term adherence.

The Bottom Line

Evidence-based lifestyle changes produce meaningful, measurable improvements. Start small, stay consistent, and trust the process.