Final answer:
Children have an easier time learning new languages due to the 'critical period,' a developmental stage where the brain is especially receptive to language acquisition. This concept combines innate biological predispositions with environmental influences, reflecting both nature and nurture in language learning.
Step-by-step explanation:
The findings that indicate children have an easier time learning a new language suggest a critical period for fluently acquiring language. This concept implies that there is an optimal time frame in early life when the human brain is particularly receptive to language learning, after which this ability declines.
Studies have shown that language acquisition occurs naturally and effortlessly during the early stages of life due to a biological predisposition for it. Noam Chomsky proposed the idea of a language acquisition device (LAD), which supports the innate capacity for language learning. However, the role of environment and reinforcement, as argued by B.F. Skinner, also plays a part in shaping language skills, making the process a combination of nature and nurture. This period of heightened linguistic sensitivity is believed to taper off after childhood, making it more challenging for adults to learn new languages with the same proficiency and ease.
Evidence of the critical period can also be seen in case studies such as Genie, who did not acquire language during the expected developmental period, and consequently struggled with mastering grammar even when vocabulary was learned. This reinforces the idea that the critical period hypothesis has a significant impact on language development.