There are 24 hours in a day. That’s an unchangeable fact, as far as I can tell (though admittedly, I never thought Pluto would lose its planet status, so I guess anything’s possible).

Should Facebook be worried about young people using Twitter more frequently? Share your thoughts.

As long as there is only a set amount of time in a day, there is only so much social networking an individual can participate in. Only so much time using the Internet. Meanwhile, more and more services are competing for our time.

Recently Google launched Google+ to cut into that time even more. If you use it, it’s taking away time from something. For some, it may be taking time away from their Facebook use. For some, it may be taking time away from their Twitter use.

But let’s forget about Google+ for a moment and consider that Twitter itself has grown significantly in popularity over the last year, no doubt helped by celebrities and the constant visibility of tweets in the media. As more people use Twitter more often, they’re taking away time that they would have otherwise been doing something else. It does not seem too far outside of the realm of possibility that for many it is taking away from their time using Facebook.

Should Facebook be more worried about Google+ or Twitter? Tell us what you think.

Various studies looking at social media demographics that have come out in recent memory have indicated that Twitter use is most prevalent among younger generations. In June, we looked at some numbers from Pew Internet, which showed that 18% of the 18-29 demographic were using Twitter. That was the highest, with 30-49 coming in at 14%, 50-64 at 8% and over 65 at 6%. In other words, the older the demographic, the less percentage using Twitter. They didn’t poll those under 18.

In my own personal experience, the trend is similar. Among people I know outside of the marketing, tech and media industries, it does seem that the most tweeting comes from the younger people.

I’ve certainly noticed the younger people (teenagers/young adults) in my family flocking to Twitter more and more, and perhaps posting updates on Facebook a bit less. In fact, one of the last Facebook updates on my wife’s sister’s Facebook Wall (she’s 18) is about wanting more followers on Twitter. My cousin, who is just a couple years older, has her Twitter account connected to her Facebook account, and most of her updates are her tweets – usually unless she’s sharing a picture, and I wouldn’t be surprised to see this behavior change now that Twitter has its own photo sharing feature in place.

Other people (and parents) I’ve talked to have noted similar trends in their families – the kids using Twitter more. One parent I talked to even said that they did not let their kid use Facebook, but does let her use Twitter. This is an interesting point to note itself.

Most Facebook posts are private, or at least limited to visibility by friends. Most tweets, on the other hand are public. Sure, you can make Facebook updates public, and you can make tweets private, but these aren’t the norms of the services. As long as we’re on the subject, Facebook just put out a new Security guide for parents, teens and educators.

Back in March, Twitter shared some growth numbers. There were 572,000 accounts created on a single day and a 182% increase in the number of mobile users compared to the same time last year. The average number of tweets being sent per day was 140 million.

Mobile has been a major driver of Twitter use, and who is on their phone more than a teenager?

Obviously Facebook is available on mobile too, but perhaps it’s the simple text message style of Twitter that the young’ns are finding appealing. Maybe it’s that less of the parents are on Twitter.

If it’s about playing where the parents aren’t, one has to wonder how the younger generations will embrace Google+ with its Circles concept.

Let’s also remember the famous words of Facebook COO Sheryl Sandberg: “In consumer technology, if you want to know what people like us will do tomorrow, you look at what teenagers are doing today…”

She was talking about email “probably going away” – a concept on which our skepticism is well documented, but it’s interesting to note that she expressed this line of thinking, as we observe how younger people are using Twitter more and more.

We might as well point out some words by Zynga’s Director of Brand Advertising at SXSW this year as well. He called 40-year-old moms the new hardcore gamers. Zynga is of course behind some of the most popular games on Facebook like Cityville, Farmville, FrontierVille and Mafia Wars. Their popular Words with Friends game also recently came to Facebook.

There are tons of younger users on Facebook (and Facebook is a much larger network than Twitter). Nobody is saying otherwise. I’d be surprised if most younger Twitter users didn’t also have Facebook accounts. The question is, whether they are using Facebook less as they are using Twitter more. Unfortunately there’s no easy way to tell this information, but it’s starting to feel that way to me.

Twitter has been more active in expanding user features since Jack Dorsey came back to the company earlier this year, than it has been in a long time (maybe ever). There is clearly a new attitude among Twitter management that is about taking care of some business.

While it’s certainly possible that Google+ will also eat into Twitter time for some users (it already has), I’d be surprised if Twitter didn’t continue to grow rapidly, and let’s not forget that the next version of iOS – the operating system that powers the ever-popular iPhone and iPad – is about to launch with heavy integration of Twitter. And we all know that “teens be iPhonein’.”

Facebook seems to be worrying about Google+ these days, but Twitter (which Facebook has borrowed heavily from in the past) just might continue to chip away at the social networking time pie.

Apparently, the wealthy are more interested in Facebook than Twitter, so that should bode pretty well for Facebook in the advertising department.

What do you think? Are younger people using Twitter more and Facebook less? Is this the case in your own personal experience? Let us know in the comments.