In the US, gender, income, and education have little impact on whether or not someone uses social media. But these factors do havea big impact on which social networks people opt to use.Many top social networksincluding Facebook, Pinterest, and Instagram have a strong skew toward female users.Women in the US are more likely to use Facebook than men by about 11 percentage points, Pinterest by 29 percentage points, and Instagram by 7 percentage points, according to Pew.But Twitter and LinkedIncontinue to attract a mostly male audience.In anin-depth report from BI Intelligence, we unpack data from over a dozen sources to understand how social media demographics and preferences are still shifting.Access The Full Report By Signing Up For A Trial >>Here are a few of the key takeaways from the BI Intelligence report:Pinterest has tremendous reach among women. Among US female internet users, 42% reported being on Pinterest in Pew's late-2014 survey, compared to only 13% of men.Instagram has become the most important and most-used social network for US teens.32% of US teenagers cited it as theirmost importantsocial network in Piper Jaffray's twice-annual teen survey, compared to only 14% saying that of Facebook.Snapchat, Vine, and Tumblr had by far the most youthful user bases of the social networks we looked at.45% of Snapchat's adult users are between 18 and 24, followed by Vine (28%) and Tumblr (28%), according to comScore.LinkedIn enjoys high adoption among highly educated and high-income users.LinkedIn is used by 44% of Americans with income of $75,000 or more, according to Pew.Messaging apps also have become more broadly popular, but still skew young:7% of all people in the US aged 12 and older use WhatsApp, according to the Edison Research and Triton Digital survey.The aging of Facebook, Twitter, LinkedIn, and even Pinterest is more apparent than ever. That's especially true of Facebook:Less than two-fifths of Facebook's adult user base in the US is aged 18 to 34, according to comScore.In full, the report:Looks at overall social networking adoption in the US and globallyAssesses the most important demographic skews at the top social networks, including Facebook, Snapchat, Twitter, Instagram, LinkedIn, Pinterest, YouTube, and TumblrExamines the rise of image-sharing social networks like Instagram and SnapchatCompares how demographics have changed over time as older social networks have maturedTo access the full report from BI Intelligence,sign up for a14-daytrial here. Members also gain access tonew in-depth reports,hundreds of charts,as well asdaily newsletterson the digital industry.Join the conversation about this storyNOW WATCH: 14 things you didn't know your iPhone headphones could do Click here to read full news..