Age: If you've never heard of it, then it's new to you.

Appearance: Like someone sitting in front of a television, furiously thumbing a dead remote.

Why doesn't this someone put new batteries in? Because it's not a remote – it's a phone.

No wonder it won't change the channel! This someone isn't trying to change the channel. This someone is chatterboxing.

Which is what, pray tell? Here's a definition from TV Licensing: "Chatterboxing (v). Watching a programme on television, whilst talking to others about that programme online, normally via a social media platform."

You mean watching TV and tweeting at the same time? In a nutshell.

I call that Telewittering. Unfortunately your word hasn't caught on. It's chatterboxing, because the TV is like a box.

Not mine. Mine's flat. Good for you.

Chatterboxing is an actual thing, is it? Yes. Forty-six per cent of 18 to 24-year-olds do it regularly.

A young person's thing, then. Not at all. More than a quarter of all adults have done it.

Don't people find it difficult to concentrate on two things at once? Apparently not. A recent instalment of Take Me Out generated 140,287 tweets; the season opener of The Only Way Is Essex got 159,603, and the X-Factor final clocked up 346,216.

So people mainly do it during programmes so moronic that no concentration is required. Not necessarily. But yes.

Why? Psychologist Corinne Sweet says: "Wanting to communicate with others when you experience emotions such as sadness, entertainment, fear or awe is a part of the human condition. As television often prompts these feelings, it is not surprising that more of us are taking advantage of evolving technology to share our thoughts."

We used to do that round the watercooler the following day. Exactly. The fragmentation of audiences was thought to have killed watercooler TV conversation, but these days we gather round a virtual watercooler.

Do say: "watchin #TOWIE @ home, bit boring 2nite but OMG WOT HAS SHE DONE TO HER BITS"

Don't say: "I miss the water."