Oxford Dictionaries has declared post-truth as its 2016 international word of the year, beating to the title other trend-setting or event-capturing terms like alt-right, Brexiteer, chatbot, coulrophobia (yes,  fear of clowns) and the rather appealing, not in the least dark, Danish concept of Hygge.

The compound word post-truth is not new and started life innocently meaning, as might be guessed, ‘after the truth was known’. In a 1992 essay, however, a new interpretation was introduced by the late Serbian-American playwright Steve Tesich. Reflecting on the Iran-Contra scandal and the Persian Gulf War, Tesich regretted that ‘we, as a free people, have freely decided that we want to live in some post-truth world’.

Post-truth now describes a scenario where truth has become irrelevant, where objective facts are less influential in shaping public opinion than emotional appeals, where what matters is whether we feel something to be true regardless of the evidence.

Understandably, the word has hit celebrity status in 2016 (usage up 2000% year on year) via its presence in the term ‘post-truth politics’ (coined half a dozen years ago by blogger David Roberts in a piece for online news organisation Grist) and its prevalence in the UK EU referendum and the US presidential election.

A defining trait of post-truth politics, amply demonstrated in these two high-profile campaigns, is the repetition of claims even if they are found to be untrue by the media or leading experts. There were too many such statements by The Donald to choose but one. Perhaps the most brazen UK example was Vote Leave’s assertion that £350 million a week would be taken from the UK’s contribution to the EU and put into the National Health Service, a protestation that was rapidly and completely dismantled. The purpose here was to fire up the voters with scant regard to reality.

Bad behaviour indeed but dishonesty in politics is nothing new. As Fintan O’Toole reminded us in the December 17th issue of the Irish Times, it was Jonathan Swift who wrote the following, in 1710, of the politician’s art: “The superiority of his genius consists in nothing else but an inexhaustible fund of political lies, which he plentifully distributes every minute he speaks, and by an unparalleled generosity forgets, and consequently contradicts, the next half-hour. He never yet considered whether any proposition were true or false, but whether it were convenient for the present minute or company to affirm or deny it…”

In passing, we should also remember that human beings do not naturally seek the truth.  In his celebrated work ‘Thinking Fast and Slow’, Daniel Kahneman recounts our preference for cognitive ease, for avoiding material that causes our brains to work hard. Unfortunately, facts, the unfamiliar and data which challenge our existing views all require elevated mental processing and, sadly, our tendency is to avoid them.

However, there are worrying signs which accompany the rise of post-truth attitudes and behaviours. When combined with the loss of trust in traditional institutions, authority figures and experts, a potential consequence is that post-truth politics trigger the acceptance of a wider post-truth society where facts are more like opinions and you can discard the ones you don’t particularly like.

We are no longer prepared to take our leaders’ words at face value; we are also more likely to believe ‘people like us’ with whom we engage on Facebook, Twitter and LinkedIn. Vertical deference has arguably been replaced, certainly challenged, by horizontal reference and, overall, that’s a healthy means of keeping us all on our toes.

But we depend upon facts, evidence and reason, cuddled by our emotions, to hold our civilisation together. However smart we are, having our feelings reinforced by unreliable soundbite “truthiness” (credit here to American comedian Stephen Colbert), whether from internet friends or the leader of the free world, is not the way forward.

And if winning by lying becomes mainstream, we are in trouble.

Previous international words of the year have included squeezed middle (2011), omnishambles (2012), selfie (2013), vape (2014) and, last year, merely the ‘face with tears of joy’ emoji. These all seem comparatively playful versus this year’s winner and all the more reason, in 2017, for us quickly to move from post-truth to post-post-truth.

Season’s greetings!