Mehdi Moussaïd, born July 23, 1981 in Rabat (Morocco), is a French cognitive sciences researcher, popular science communicator and web video creator. Born to a French mother and Moroccan father, he studied at the Lycée Descartes in Rabat and then trained as a computer engineer at École polytechnique universitaire de Nantes. He defended his PhD thesis in ethology in 2010 at Toulouse-III-Paul-Sabatier University under the supervision of Guy Théraulaz and Dirk Helbing, earning the 2011 Prix Le Monde de la recherche universitaire. He joined the Max-Planck Institute for Human Development in Berlin as a postdoctoral researcher in cognitive sciences, where he soon obtained a permanent position. He is best known for his crowd-behavior YouTube vulgarization channel Fouloscopie, created in 2018. He moved to La Rochelle in 2023. In 2019, he published Fouloscopie: ce que la foule dit de nous (HumenSciences, illustrated by Wozniak, 224 p.), and in 2025 his second mainstream essay A-t-on besoin d'un chef? The same year, he founded Fouloscopie Lab, a training organization specializing in collective intelligence.
