David Lagnado: "Scales of injustice: Why a balance metaphor can be misleading when weighing evidence"

Speaker: Prof. David Lagnado, PhD, Professor of Cognitive and Decision Sciences, University College London, UK

Title: Scales of injustice: Why a balance metaphor can be misleading when weighing evidence

Abstract: The metaphor of the scales of justice, where evidence tips the balance in favour of one party or the other, is pervasive in law and beyond. It is also reflected in how people balance arguments for or against a position in everyday reasoning. At the core is the idea that evidence is zero-sum, that it speaks to one side or the other. This zero-sum concept depends on critical assumptions about the competing claims, namely, they are mutually exclusive and exhaustive. When these assumptions do not hold, which is common in many real-world disputes, the weighing metaphor can be misleading.