The next time you hear someone lament about how Millennials constantly have their eyes glued to their smartphones so they can check their Facebook status for the umpteenth time, or to count how many new likes they got on their latest LinkedIn post, tell them about the new study by Nielsen.

When Nielsen analyzed data from 9,000 smartphone and 1,300 tablet users from across the US from July through September 2016, they found that the older folks -- the Generation X'ers (35-49 year-olds) -- spend even more time on social media than Millennials. Generation X'ers spend six hours and 58 minutes on social media each week, nearly 40 minutes more than the six hours and 19 minutes that Millennials (18-34 year-olds) spend on social media.

Not surprisingly, both of these demographic groups spend far more time on social media than adults 50 and older -- the Baby Boomers -- which spend, on average, four hours and 9 minutes on social media weekly. But don't write-off the older generation quite yet: While Adults 50 and older may be spending much less time than their Generation X and Millennial counterparts, the time they do spend is growing at a far faster clip.

In Q3 2016, the period of Nielsen's survey, adults 50 and up spent 64 percent more time on social media than the same period in 2015. During the same time, Millennials spent 21 percent more time on social, while Generation X'ers spent 29 percent more time.

So where are these social media addicts spending their time, and what are they doing?

Of the top 10 social network platforms that people used on their smartphones in September 2016, unsurprisingly, Facebook came out on top with 178.8 million unique users across both its app and mobile website. That's twice as many users as second-place Instagram, with 91.5 million users.

Twitter, Pinterest, and LinkedIn followed with 82.2 million, 69.6 million, and 60.1 million unique smartphone users that month, respectively. Snapchat fell just behind LinkedIn with 52.6 million unique users, a number that doesn't surprise me as it's a platform that resonates more with the under-18 Generation Z demographic, which Nielsen didn't cover in its study.

Nielsen also looked at "second-screening", the habit of using social media while watching a TV program. On average, 58 percent of smartphone users said they visited Facebook while watching a program, compared with 20 percent who said they visited Twitter.

Again, Generation X surprises us: On an average day, 42 percent of those interacting with TV on Facebook are Generation X, 40 percent are Millennials, and the remaining 18 percent are Baby Boomers.

And the bulk of second-screeners are women: 61 percent of users, compared with just 39 percent that are men.

Nielsen cites the top three reasons people are second-screening on their smartphones: Looking up information on actors and athletes they're watching (25 percent); chatting with friends about the program (23 percent); and sharing photos (19 percent).

One lesson marketers can draw from this data is to look at the data first, before drawing conclusions about consumer behavior. The Nielsen study offers a rich glimpse into how the three biggest demographic groups in America use social media today. The surprising insights it offers, particularly around the differences between Millennials and Generation X'ers, can help you calibrate your social media strategy.