“Cognitive development refers to how a person perceives, thinks, and gains understanding of his or her world through the interaction of genetic and learned factors. Among the areas of cognitive development are information processing, intelligence , reasoning, language development , and memory”[1]. Language and cognitive development are both acquired via learning and interacting with some other persons. None of them can be achieved in isolation. As humans we are of coursed influenced by our environment. A child would only learn to speak the language it hears others around him speak and of course learning process begin even before language because language has to be learnt.
 

[1]http://www.healthofchildren.com/C/Cognitive-Development.html#ixzz6uIMVWNbj