The proportion of internet users aged 18-29 who reported using social networking sites dropped to 83% in December 2012, according to results from a study by the Pew Research Center’s Internet & American Life Project. That represents a 10% decline from just 4 months earlier, and is the lowest proportion in roughly 2 years. Overall, after rising steadily for several years, the percentage of internet users who reported using social networking sites dropped for the first time between August and December 2012, down from 69% to 67%. (It’s worth noting that because the data refers specifically to internet users, the actual number of Americans using social networking sites may have increased, depending on the speed of growth of the online population.)