Around 65 percent of U.S. adults who use the Internet are using social networking services like Facebook, LinkedIn and Myspace, up from 61 percent in 2010. That figure is more than double the percentage of adults who said they were using social networking services in 2008 (29 percent) and means that 50 percent of all adults in the U.S. are using such services.

The study, which was carried out by Pew Internet and quizzed 2,277 adults about their Internet usage, found that 43 percent of adult Internet users say that they use social networking services on a typical day — up from 38 percent in 2010 and 13 percent in 2008. Email (61 percent) and search engines (59 percent) are the only online activities being used more often than social networking services on a typical day.

Among those who use the Internet, social networking services were found to be most popular with women and those aged under 30. Around 89 percent of online women aged 18 to 29 use social networking services, with 69 percent accessing the services on a typical day.

It was found that 69 percent of women are using social networking services, compared with 60 percent of men. Women also accessed these services more frequently — 48 percent use them on a typical day, compared with 38 percent of men.

The study found no significant differences in the use of social networking services based on social demographics such as race and ethnicity, education level, household income. The adoption rate of social networking services did not vary much depending on whether the Internet user lives in an urban, suburban or rural environment either.

However, there were some significant differences when it came to age groups. Usage of social networking services by adults aged 18 to 29 actually dipped slightly from 2010 — 83 percent of Internet users in that age range are using these services, down from 86 percent a year ago. Meanwhile, usage among all other adult age ranges has increased.

When it comes to how often people in various age ranges are using social networking services, the scenario is a little different. The percentage of those aged 18 to 29 who use these services on a typical day did not change much, rising by just one percentage point from 2010 to 61 percent. However, there were significant increases in daily usage among those aged 30 to 49 and 50 to 64 — from 39 percent to 46 percent and 20 percent to 32 percent, respectively.

While it may be suggested that adoption of social networking services has reached its peak among younger adults, it is important to remember that this age group is often the first to try out new services. This study does not tell the full story either, as it does not provide a breakdown of which services are being used. Indeed, a previous Pew Internet study showed that around 13 percent of U.S. Internet users are on Twitter, meaning that there is a vast opportunity for that service’s user base to increase.

When asked to use one word to describe their experiences of using social networking services, the most common word used by respondents was “good.” Positive responses were more frequent than negative and neutral words. More common positive words included “fun,” “interesting,” “great” and “convenient.” However, around 20 percent of respondents who answered this question responded with a negative word or even an expletive.

This data follows on from a previous Pew Internet study, in which it was suggested that Facebook users tend to have more close friends.