Whorf's work began to fall out of favor less than a decade after his death, and he was subjected to severe criticism from scholars of language, culture and psychology. In 1953 and 1954 psychologists Roger Brown and Eric Lenneberg criticized Whorf for his reliance on anecdotal evidence, formulating a hypothesis to scientifically test his ideas, which they limited to an examination of a causal relation between grammatical or lexical structure and cognition or perception. Whorf himself did not advocate a straight causality between language and thought; instead he wrote that "Language and culture had grown up together"; that both were mutually shaped by the other. Hence, has argued that because the aim of the formulation of the Sapir–Whorf hypothesis was to test simple causation, from the outset it failed to test Whorf's ideas.