‘WHO do you think you are?” No, don’t worry – this isn’t an angry quote from a Channel Four interview conducted in the heart of Trumpland (or for that matter, Leavetown).

Readers of the Radio Times will recognise it as this week’s front cover headline, heralding the return of the BBC’s successful family history show. Inside, we discover Eastenders’ Danny Dyer is a distant relative of William the Conquerer, Edward III and Oliver Cromwell. Well, thanks for that.

The routine for the new series of Who Do You Think You Are? looks the same as it’s been since 2004. It’s easy to be a cynical pundit here. Wait for the money shot when the tears drop from the D-lister’s eyes, narrowly avoiding the trembling parchment in their hands. And given that most of them are professional emoters, that might not inspire the greatest emotional confidence.

But maybe cynicism is exactly what we don’t need. Amidst the general clamour of identity politics at the moment, it is fascinating to note just how deep, wide and enduring the interest is in tracing our personal roots.

There was another genealogy story this week which brings the quest for family history a bit closer to the pulse of current events. The new Oxford Dictionary of Common Family Names is out, which has identified the most common surnames on these islands. They are (in descending order): Smith, Jones, Williams, Brown, Taylor, Johnson and Lee.

So that’s two trades (metalworker and tailor), three patriarchies (sons of John and William), one forest clearing (the Old English lēah means “meadow), and one all-purpose colour description (and what is more Britannic than brown?).

For comparison, Scotland’s top seven surnames has Smith and Brown at the top, two alternative patronymics (Thomson and Robertson), and adds in Campbell (from the Gaelic for “wry-mouthed”) and Stewart (meaning “warden of the hall”) at numbers 6 and 7.

It’s hard to read all that and not feel the weight of a long-standing power structure.

Also, we are told that half of the 20,000 most common names are “locative” – meaning they come from places (eg Green, Hill, Wood, Townsend). So no matter how many of us are thrown around the world, our names carry some pre-modern traces of those limited locales in which humans have grown and developed.

The Oxford dictionary researchers are thoroughly alive to the politics of the moment, pushing some of their quirkier discoveries at us. For example, “Farah” isn’t just the name of the beloved sportsman (and Arabic for “joy, happiness and delight”), but also an Old English term (standing for farrier, or blacksmith). “Levison” may also seem like it has an obvious Jewish derivation – son of Levi – but the Oxford scholar also tells us it could be a Northern-English compression of the Scottish “Livingstone”.

Now, especially at a time when people are screaming about defending their “authentic identity” against the diversity of the planet, the genealogy biz can jangle the nerves. To quote the sociologist Paul Gilroy, genealogy should be about “routes” as well as “roots”. That is, about the mixed and tangled pathways our ancestors took, as much as tracing any “blood-line” stretching into the past.

As a show, Who Do You Think You Are? can be good at “routes”. And sometimes when the sniffling starts, it isn’t obviously thespians turning on the tap, but a genuine challenge. At the height of his pomp, we saw Jeremy Paxman choke up at the news of the poverty of his Glaswegian ancestors – that wasn’t easily forgotten. Ainslie Harriet’s confusion and consternation at discovering one of his ancestors was the descendant of a white slave owner didn’t seem faked.

The nerves get janglier the closer one gets to biology. The genealogy industry has created another marketplace recently, with the advent of genetic testing. This claims to trace some of your primal ancestors by identifying markers that are consistently passed down through elements of your DNA – Y chromosome on the father’s side, mitochondria on the mother’s side. “one million UK men are part Viking” is a familiar headline.

There’s some serious scepticism here. Science broadcaster Adam Rutherford last year wrote that “these two chunks of DNA make up two per cent of your genome. But the other 98 per cent has to come from somewhere too, and that is a pick-and-mix from all the rest of your ancestors.”

Rutherford continues that “because of the way the DNA deck is shuffled every time a sperm or egg is made, it doesn’t keep halving perfectly as you meander up through your family tree… [Your grandparents’] genetic contribution to you is not equal. Before long, you will find ancestors from whom you bear no DNA. They are your family, your blood, but their genes have been diluted out of your bloodline.”

To be fair, we’re only at the start of mapping the human genome. And what that messy 98 per cent tells us definitively is that the idea of anyone having racial purity, no matter what they’ve tattooed on their back, is patently ridiculous.

Yet “who we think we are” – and defending that against Otis Redding’s old complaint (“can’t do what ten people tell me to do”) – increasingly demands some kind of answer, or substantiation. A nuanced, worldly story would be best. But the basic need seems to be undeniable The Catalonian thinker Manuel Castells anticipated this urge nearly 20 years ago (in the pages of our sister paper, The Herald). Castells predicted then that a network society, furiously connecting up and reprogramming everyone through its information systems, would generate a counter-reaction.

Populations would search for an identity, history or ground, into which they could drop an anchor, as the storm of this future raged around them. Castells described these polarities as “the net” and “the self”.

And here we are in America and Europe, grappling with a politics – not yet in Scotland, but no complacency – that is in part fuelled by an angry assertion of “the self” against “the net”, of secure and solid identity against the quicksilver processes of globalisation. Traditional political forms and forces have fallen down the gap between these polarities (again, we’ve lucked out in Scotland, having been building a civic, left-of-centre, outward-looking nationalism for about 40 years).

Millions need to fill that gap with something that integrates them – something that makes sense of their ever-more-demanding lives on this connected planet of ours. And it may be that exploring your both your “roots” and your “routes” is exactly the kind of complex anchor that modern people need.

The French philosopher Paul Ricoeur wrote beautifully about our need for a family archive. “We tell stories”, he wrote, “because in the last analysis human lives need and merit being narrated. This remark takes on its full force when we refer to the necessity to save the history of the defeated and the lost. The whole history of suffering cries out for vengeance and calls for narrative.”

Constructing our own small personal tales can help us get the measure of historical forces which often seem to overwhelm us.

So it may require the deployment of D-listers, jobbing TV presenters and Cockney soap stars. But “Who Do You Think You Are?” is asking the right question and answering it in probably the right way.

lWho Do You Think You Are? is on Thursday on BBC1 at 8.00pm. The Oxford Dictionary of Family Names in Britain and Ireland is £400 – your library can order it.