Key Theorists and Concepts in Language Acquisition and Development

Noam Chomsky

Created the theory of Universal Grammar (UG) and the Principles & Parameters framework; central figure in the Innatist view.

Stephen Krashen

Created the Monitor Model, including the Input Hypothesis, Affective Filter, Natural Order, Acquisition-Learning, and Monitor Hypothesis.

B.F. Skinner

Developed the behaviorist theory of language learning based on operant conditioning (stimulus → response → reinforcement).

Ivan Pavlov

Created classical conditioning theory, which inspired early behaviorist views of language learning.

Eric Lenneberg

Proposed the biological foundations of language and the Critical Period Hypothesis (1967).

Larry Selinker

Created the concept of Interlanguage and introduced fossilization and developmental processes in L2 learning.

Roger Brown

Discovered the Morpheme Acquisition Order in child language (e.g., -ing, plural -s, irregular past, etc.).

Dulay & Burt

Identified the L2 English grammatical morpheme acquisition order among children from different language backgrounds.

Dörnyei

Created the L2 Motivational Self System (Ideal L2 Self, Ought-to L2 Self) and a framework for classroom motivational strategies.

Senghas

Researched and documented the emergence of Nicaraguan Sign Language (NSL), showing how children create grammar.

Russ Rymer

Wrote the case study 'Genie: A Scientific Tragedy,' documenting critical period effects in extreme deprivation.

Kinginger

Created research on study-abroad experiences, identity, social networks, and why language gains vary widely.

Pica

Developed methods showing that accuracy in obligatory contexts alone doesn't prove true morpheme acquisition.