Independent Thinking

Deeper Explanation

Independent thinking is the foundational psychological characteristic required for sustained contrarian investing. Without the ability to form and maintain views that differ from the consensus, the investor is structurally limited to consensus returns. With it, the investor creates the conditions for the above-average returns that contrarian investing can produce when the analysis is correct. Independent thinking is harder than it sounds, for reasons deeply rooted in psychology. Social proof — the tendency to look to others for guidance on what is correct — is one of the most powerful influences on human behaviour. In financial markets, it is reinforced by career risk: the professional investor who is wrong with the consensus suffers less professionally than one who is wrong while being contrarian. This asymmetry systematically biases professional investors toward consensus, even when their private analysis would suggest a different view. Marks has identified several specific habits of independent thinking. First, reading voraciously and broadly — including sources that challenge your existing views rather than confirming them. The investor who only reads the sell-side research that confirms their thesis is actively restricting their ability to think independently. Second, maintaining a research diary — recording the thesis, the key assumptions, and the reasons for conviction at the time of purchase — so that subsequent developments can be assessed against the original analysis rather than against hindsight. Third, seeking out the best counterargument to every thesis held with conviction — genuinely engaging with the case against the position rather than dismissing it. Independent thinking does not mean being contrarian for its own sake — it means being willing to hold views that differ from the consensus when the analysis justifies it, and being willing to hold the consensus view when the analysis supports it, regardless of which direction social pressure is pushing.