Funding agency: Agence Nationale de la Recherche - ANR 

Scientific partners: 

• Paris 2 Panthéon-Assas

• Institut de Sciences Cognitives Marc Jeannerod

• EM Lyon

Duration: 10.2025-09.2029

Funding: 438.000€

Human societies are extremely hierarchical. Decision making is centralised, salaries are differentiated, functions are distinguished in terms of importance or prestige. Hierarchical social organisation evolved in such tight connection with human societies to become deeply rooted in the biology and evolutionary history of our brains. We use dominance cues (e.g., body size, facial features or, income) to rapidly assess relative rankings. Research in psychology, cognitive science and neuroscience has documented how neurobiological processes preside over individuals' understanding of social interactions under hierarchy. Economic hierarchies may not be exempt. By ranking individuals, inequality may independently organize behaviours. Clear evidence for this effect is missing. Economic hierarchies are inherently confounded by correlates to income, such as prestige, power, skill, and importantly, income itself: at the same time, income differences imply differences in affluence and in rank. We thus define a hierarchy as the ranking of individuals along a monetary (scalar) distribution, while income, and its correlates defining broader notions of status, are treated as confounds.

Our first level of investigation is behavioural: we aim to observe how economic hierarchies, absent confounds such as income and its correlates, organises behaviours. We focus on (un)ethical behaviours and patterns of social influence and decision-making along the income distribution.

At a second level, we will investigate the neurocognitive mechanisms underlying behavior related to monetary hierarchies. To this end, we will employ experimental protocols designed to assess potential attentional biases associated with these hierarchies (for instance, through eye-tracking measures). In addition, we will develop and estimate value-based computational models that account for the observed behavioral patterns and examine how specific model parameters relate to brain activity recorded during decision-making (using fMRI).

We aim for a better understanding of the impact of economic inequality on individual and social behaviours, and of the level (cognitive, neurobiological) at which inequality as a hierarchy expresses its effects. An advantage of high-income individuals' persuasion abilities—resulting not from skill or knowledge, but from the cognitive processes activated in others by their rank—could grant them disproportionate influence over policy.  Organizations are characterized by a hierarchy with a leader who determines outcomes and actions. The leader's ability to garner support is a crucial determinant of their success. Affluence increasing leaders’ persuasiveness would advantage one set of policies: outcomes may be socially sub-optimal should the leaders’ and societal preferences be misaligned.