IT sounds like a mating dance for hipsters: virtue signalling.

My gran used to have a cross stitch with the words, “Do not choose for anyone what you do not choose for yourself.” She also had a wooden spoon that read, “You’re never too old to spoon,” though, despite repeated insistence, no one would ever explain what this meant.

This was virtue signalling in the days before the internet: a fine, upstanding wall hanging and the wink of a light sense of humour.

Now, instead of lining the walls of our homes with hints to our characters, we line our virtual walls with signs of our virtue.

Mandatory emoting, the new status symbol, involves, for example, changing your Facebook profile picture to the rainbow flag during Gay Pride. Currently, if you’re in the right, that is to say, on the left, you’ll have I Welcome Refugees across the bottom of your photograph.

A hangover of the referendum campaign is small 45 symbols in the corner of peoples’ avatars, semaphore for the fact independence supporters are in the virtuous minority of those who wished for a better future for Scotland.

There’s a type of competitive linguistics that goes alongside this: posts will be sure to say refugees instead of migrants. They’ll express a belief in the NHS. They will slap down any sniff of conservative sentiment.

Facebook, it was just announced, is to introduce a new “dislike” button to match the “like” button for statuses.

It’s going to be a “quick way to emote”. “Not every moment,” Mark Zuckerberg, the company’s founder, says, “is a good moment.” It’s a virtue signaller’s heaven. You don’t need to fuss about with pasting twibbons on your profile picture, you don’t have to agonise over the correct semantics of the politically correct, liberal status updates. You just click. Click to dislike David Cameron’s visit to your local shopping centre. Click to dislike Kezia Dugdale’s latest policy announcement.

The charge of virtue-signalling is a lazy tool of those on the right to condemn the left as woolly-thinking and naïve when they have run out of comebacks when under attack for their desire to cut benefits or shrink the welfare state or send their children to private school.

But I wonder if there isn’t something in it. How many of those who sent their profile pictures rainbow coloured marched in the Pride march? How many who Welcome Refugees would welcome a refugee into their spare room? How can you have open debate when people feel the need to join opinion gangs?

Bite-sized is becoming button-sized. Button-sized emotions and button-sized reactions. It’s so easy to publicise what you stand for without standing up.

Britain is now opening its doors to more Syrian refugees because people marched, not because they clicked. Because they wrote letters of support, not because they changed their profile picture.

At the same time, there’s much to be said for online campaigns: the Ice Bucket Challenge, which raised millions of pounds and dollars for a variety of charities, is a great example of that.

It’s not all sofa-based slacktivism, however. Social media also makes it easy to publicise ones good works: zip-sliding the Clyde? You’ll get a shower of likes for that. Abseiling the Forth Rail Bridge? Let everyone know. Social media allows ease of fundraising, publicity and the warm glow of appreciation from those around you for the people who want to take their right-thinking and make it right-doing.

At least a desire to be seen to be in the virtuous social media circle helps make Facebook and Twitter nicer places to be. With the amount of digital harassment and trolling happening online, competitive virtue is a salve.

It's how to spill online goodwill into offline action, is the challenge. Maybe Zuckerberg can develop a button for that.