2) Eventually Lacie succeeds in attracting the attention of a childhood friend with a rating of 4.8. The friend invites her to the wedding and asks her to speak for several minutes as the bride’s closest childhood friend before hundreds of guests, all rated above 4.6. This is an exceptional opportunity for Lacie: a sudden flood of high ratings could lift her into the social position needed to buy her dream home. It does not even matter to her that this supposed childhood friend had been involved with Lacie’s partner and that Lacie knew it. She knows many unpleasant truths about this friend, yet intends to give a speech praising her goodness because the valuable likes from that elite audience can make Lacie more important and wealthier.

On the journey to the wedding, Lacie encounters a series of unforeseen events that send her social rating into free fall. The problems begin with a cancelled flight and an angry argument with an airline employee, and they continue throughout her difficult journey until her score falls to 2.1.

When she is close to the wedding venue, her friend Naomi telephones and tells her, to Lacie’s disbelief, that she should no longer attend. With a social rating of 2.1, Naomi says, Lacie’s presence would only embarrass her before the guests. The story continues until Lacie’s score falls to zero and she is imprisoned. Only then does the persona finally fall away and a face long concealed behind her social mask become visible.

At one point in the story, an older woman with a rating of 1.4, who drives a truck, gives Lacie a lift and has a deep and interesting conversation with her. She tells Lacie that she once had a score of 4.6. Her husband had a score of 4.3 and developed cancer. He died partly because their rating did not give him access to resources reserved for people above 4.4. The experience forced her to reconsider seriously how she was living. She decided to become honest with herself and others, removed her mask, and quickly discovered that in a world that measures human worth through ratings, almost no one cares about honesty.

The people who had seemed to be her friends began to disappear, because the real relationship between them had been little more than an exchange of ratings. Yet as they fell away she felt gradually lighter and freer from lies, like taking off a pair of shoes that had always been too tight.

The older woman asks Lacie what she actually wants, what she is trying to reach and what she is fighting for. Lacie answers: happiness—to be able to take a deep breath and feel content. But she believes she has to keep playing the absurd rating game until she reaches that point because this is how the world has been designed: a world in which the importance of people, ideas and almost everything else is determined by public opinion and social ratings.

This Black Mirror episode offers a caricatured and exaggerated but recognisable image of our own world. It asks: what is the relationship between our value and our likes? What is our relationship to other people, to the world around us and to what appears before us? What place do honesty and truthfulness towards ourselves and others have in this world? How much depth remains behind our social mask?

It is often said that in ordinary free conversation people spend around forty per cent of their speaking time talking about themselves. Perhaps a similar proportion of our social-media posts are usually about ourselves: our thoughts, photographs, places we visit and matters connected directly with us. One might therefore imagine a simple division: people whose social-media content is more than forty per cent self-referential and those whose content is less. Now consider the question: what percentage of the posts you share and then wait for others to like are about you personally? I leave the judgement of what this distinction means, and where you place yourself within it, to you. But I would like to make two further points: one about the likes we personally receive, and another about the likes received by non-personal material that we share because we regard it as valuable.