Language Acquisition

http://www.youtube.com/watch?v=RE4ce4mexrU

I found this video very interesting and quite related to Krashen's Natural Approach. Language acquisition is analysed by Deb Roy, an MIT researcher, who acquired more than 90,000 hours of  video and 140,000 hours of audio footage recorded over a span of 3 years in his house. Roy used the data to help him understand how his infant son acquired the ability to speak the English language. Although the clip is about 20 minutes long, it is quite astonishing to hear and watch the progress of how humans learn to speak.