Final answer:
Infants develop receptive language skills by recognizing and understanding words and sounds, an ability that precedes and aids in developing productive language, where they actually produce language. Both nature and nurture contribute to language acquisition, supported by the interplay of genetic predispositions and social interactions.
Step-by-step explanation:
Infants develop receptive language very early on, beginning to recognize their mother's voice and the language spoken by her, showing the innate cognitive abilities to learn language. Receptive language is the ability to understand words and language - a foundation essential before expressive or productive language, which is the ability to produce language forms, can develop. The first one is about understanding and processing information; the latter is about language output, the actual speaking or signing.
According to behaviorist B.F. Skinner, language learning comes from reinforcement - a child communicates a need, and the caregiver's response reinforces the association between the word and its meaning. In contrast, Noam Chomsky proposed that children are born with an innate capacity to learn languages, evolving the debate into one where both nature and nurture play crucial roles in language acquisition. This capacity is reflected in Chomsky's theory of a Language Acquisition Device (LAD), and the critical period hypothesis suggests that there is an optimal period for language acquisition in early childhood.
The difference between receptive and productive language is also tied to the stages of child development. As babies grow, they first understand words and sentences (receptive language), and then later start to speak or sign themselves (productive language). These phenomena occur widely, irrespective of the specific language or culture - pointing to biological as well as environmental components to language development.