2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/140802This is a programmatic paper, marking out two directions in which the study of social media can contribute to broader problems of social science: understanding cultural evolution and understanding collective cognition. Under the first heading, I discuss some difficulties with the usual, adaptationist explanations of cultural phenomena, alternative explanations involving network diffusion effects, and some ways these could be tested using social-media data. Under the second I describe some of the ways in which social media could be used to study how the social organization of an epistemic community supports its collective cognitive performance.6 pages, 1 figure, AAAI format, submitted to AAAI spring 2008 symposium on "Social Information Processing"Computers and SocietyPhysics and Societytext