Noam Chomsky
Noam Chomsky is an American linguist who contributed greatly to Cognitive psychology through language research. Chomsky challenged the Behaviorist view that language, like any other behavior, was learned through exposure to language in the environment. Chomsky theorized that all humans share an innate capability for language unlike any other species of animal and that our capacity for language was the same no matter what culture or environment we are exposed to. Evidence for this theory can be seen in a household with a baby and a kitten.
Although both are exposed to human language from the time they are born, only the human child eventually develops the ability to speak. Chomsky coined this innate capacity for speech in humans the Language Acquisition Device (LAD). Chomsky's theories were revolutionary at the time and were integral in the Cognitive Revolution of the 1950s-1960s.