Age is one of the important aspects in physiological researches of linguistic aptitude.
The most common explanation for these observations is that there is a "critical period", during which the brain is flexible and language learning can occur naturally and easy. Around puberty is considered to be the period one can no longer call upon the learning capacities.
We suppose that linguistic aptitude, as the specific psychological feature of a man, is very important not only in formal situation (as Krashen thinks), but in any kind of situation. Therefore to study the process of aging from a linguistic point of view is the question to pay attention to.
Those scholars, who agree that age-related differences in SLA exist, have been suggested in the following explanations: social-psychological, cognitive, input and neurological. But, obviously, in this area as in many others, much work remains to be done.
We studied the development process of the specific component of linguistic aptitude – the comprehension of fitness between the sound of a word and its meaning – in the junior school age and saw that exposure of this ability has a natural character, it’s in correlation to the linguistic memory, develops according to the increasing of age, which is connected to our mind, to the development of metalinguistic or objectivation ability.
The moment that correlation between the denoted ability and mnemonic effect is high in the 1'st form, means that mnemonic effect is more important with the six-year old children, than with the children of the later ages.