The document discusses several relevant aspects of age and second language acquisition. It addresses the critical period hypothesis, which suggests there is an optimal period for acquiring language. Research on first language acquisition found age was less important if proper environmental stimuli were not present during crucial stages. Cognitive development also impacts language acquisition, as formal thinking abilities emerge around puberty. Emotional factors and a person's first language can also influence how a second language is acquired. The relationship between language and thought additionally affects the process as new concepts must be sorted from existing knowledge.