Working and interacting in foreign languages is widespread. While the relationship between language and behavior has been discussed for many years, empirical evidence for behavioral effects of foreign language use is surprisingly scarce. Stefan Nothelfer has conducted a series of laboratory studies to investigate and disentangle effects of language and culture on creativity and cooperation, important behavioral foundations of innovation. He draws insights from a large cross-country dataset with pairings between three languages, using a custom-built mobile laboratory. The author’s findings challenge theories of linguistic relativity, foreign language effects, and cultural accommodation, and enrich the empirical basis for fundamental research on language and behavior.