Realist theory of adjudication to the test of cognitive science

Being characterised by the centrality of legislation, one may say that Western legal theories have been grounded on a sort of Kahneman’s System 2 rational thinking. In his researches on the nature of thought, choice and decision, Kahneman has outlined how two different mental processes (heuristics-fact System 1; deliberate-slow System 2) interact within reasoning and decision-making (Kahneman 2011). Over the past decades, a number of inquiries on normative practical reasoning has grown widely. For instance, in the field of moral psychology, it has gone from views of morality based on abstract rules to perspectives emphasising the coexistence of additional factors in moral deliberation (Haidt 2001; Greene 2004). Brought to the legal domain, such inquiries have shown that the judicial-decision process is more alive to the influence of heuristics and cognitive social biases, then generally admitted. Indeed, since the early decades of 20th century, realist legal scholars such as Jerome Frank (1949a, 1949b) and Alf Ross (1946, 1959) explored the psychological grounds of judicial decision-making. Reassessed with new sensitivity, their insights prove that a realist view is the most viable alternative in both theories of legal sources and judicial adjudication, by keeping pace with the latest advancements afforded by cognitive science.