The stateside popularity of Downton Abbey has observers on both sides of the shining sea trying to shake out the secrets of the show's American triumph. But for half-British, half-American couples with their own private take on the Special Relationship, much of the fascination turns on the understated intercultural playbook of Lord Grantham and his curvy-as-a-dollar-sign wife.
In our half-sceptred, half-star-spangled eyes, the show reminds us that some truths of transatlantic coupledom are apparently timeless. And they become particularly vivid after a move from one half's home country to the other's, as when my British partner and I recently decamped from London to New York.
It's not that New York has unearthed disagreements on any traditional Anglo-American fault lines. On Special Dilemmas from whether people should be thanked or hanged for suggesting that others should "have a nice day", to which country has more dumb rules, we're on the same side (or long ago accepted the other's lovable ravings).
But the stateside move has revealed some new intercultural fender benders in the food department. Some, it turns out, were long simmering, as when – to choose a recent example – a certain British half says to their American half, it's all very well and good you've learned how to make Victoria sponge cake, but you've been serving it at the wrong time all these years – in the name of Boudicca it is not an after-dinner dessert.
If our relationship requires I eat more cake in the afternoon, so be it. But on another issue, there will be no peace, no accommodation – only a tumbleweed-swept, Atlantic-sized, barely demilitarised zone across which we glare with a ferocity not seen since 1776. I speak, of course, of peanut butter.
It's not that Britons don't eat peanut butter – they bought about £50m worth of it last year, according to Mintel, a market-research firm. But Businessweek reports Americans spend about $1.8bn (£1.1bn) a year on it – almost five times as much per capita. On either jam or honey, Mintel's research shows that Britons spend twice as much as they do on PB; even British marmalade expenditure exceeds peanut butter outlays. Americans, by contrast, spend about as much on peanut butter as on regular butter. Its jaw-cementing joyfulness is at home in an astonishing 91per cent of American households. With allergy prevalence running at about 2 per cent, it's not a stretch to suggest that nearly every American household without allergy concerns is buying it.
Including half of ours. Home in a land that embraces PB with an enthusiasm otherwise reserved for toppling Third World dictators, I've fallen in love all over again. On sandwiches – with jam, with bananas, or alone on bread, the highest calling of which, I've rediscovered, is as a convenient peanut butter carrying case. It makes celery palatable, desserts delightful, apples and bagels extraordinary, though it's at its finest straight from the jar, its glories unmoored from lesser angels.
My partner remains unconvinced. When I read aloud the descriptions of PB-graced desserts on an American menu, the look of sad disdain suggests I may as well have rolled up a dollar bill and grabbed a hand mirror. We've agreed to disagree, of course, but in the context of our own asymptotic cultural convergence (not to mention Britain and America's), it's the small differences that are often most interesting.
"But seriously, why don't you like it?" I ask.
"Because it's disgusting."
Such reactions aren't unusual: for many adult Britons, peanut butter conjures a revulsion only slightly less Manichaean than Marmite – whereas for Americans, a distaste for peanut butter is about as rare as a dislike of English accents.
For expert insight into this nutty disconnect, I turned to Max Clark, a teacher at Leiths School of Food and Wine, and co-author of Leith's Meat Bible. Ms Clark is in some ways the British exception that proves the rule, having fallen early and hard for peanut butter. First as a welcome childhood alternative to something "rather ominously called 'Sandwich Spread'" – then as the crowning glory of a long-ago concoction at her local sandwich bar, a four-out-of-five-days tower of crispy bacon, iceberg lettuce, mayo, redcurrant jelly... and crunchy peanut butter. Today she recommends PB for sandwiches of all sorts, for baking, of course, in Thai cuisine and as the lynchpin of a mean sambal sauce.
Professionally though, if not personally, she recognises the palate uprisings that peanut butter can induce in her compatriots. It may be a texture thing, she suggests – the "viscous, mouth-coating" quality that Brits may find "fantastically repulsive". Then there's the question of the PB&J, the iconic American peanut butter and jelly sandwich, of which the average US child is said to eat 1,500 or so by age 18. Perhaps the concept troubles a more fundamental (and as-yet uncorrupted) British loyalty to jam – that "it just feels wrong to mix it up"?
British consumers also tend to eat peanut butter earlier in the day and earlier in life. According to Mintel, breakfast is the repast of choice for about three-quarters of British peanut-butterers, as against just 28 per cent for lunch. American numbers are more or less the reverse (not to mention the 19 per cent who have it at dinner). And while 59 per cent of British households with children aged between five and nine buy peanut butter, just 32 per cent of single-person households do. In America, two-thirds of PB is consumed by adults. Perhaps peanut butter's most fundamental British problem is that it can't quite loosen its children's-breakfast-food shackles.
Whatever the reasons, though, peanut butter is one of the nails protruding from the well-varnished structure of the Special Relationship – and it's time to hammer it in.
Realism dictates we not ask Americans to reduce their consumption of peanut butter (or petrol, or anything else) to British levels. Instead, the focus has to be on supersizing Britons' PB uptake – something that at this point we'd still like to accomplish peacefully, without resorting to air strikes on your marmalade factories.
British consumers tend to be more health conscious than their American cousins, so perhaps that's the best opening salvo. The US government approved a heart-health claim for peanuts back in 2003. Even if you assume the entire apparatus of American statecraft rests in the sticky clutches of peanut lobbyists, there's always the EU, which said just last year peanut butter has an important role in cholesterol regulation.
Then there's the weight-loss possibilities. Britain, in its sensible halfway-house between the Continent's historically intact cuisines and America's latest food neuroses, may be well-placed for the peanut butter diet. There's even a book, The Peanut Butter Diet (which tells us how to lose weight while still enjoying peanut butter every day) and occasional comparisons to the Mediterranean diet. (Take that, Italy!) Meanwhile, a friend suggests a CIA or Blackwater-led covert campaign to replace the peanuts in British pubs with little tubs of peanut butter.
If serious health claims, whack-job diets and bar-top sleights of hand aren't quite up to the task of quintupling British peanut-butter consumption, we can always appeal to Britons' growing interest in home-crafted delicacies. Clark, of Leiths, says it's "ridiculously easy" to make your own peanut butter: put roasted peanuts in a food processor until the contents resemble peanut butter. If you're feeling fancy, add salt and honey to taste.
Then she pauses; what she says next brings red, white and blue tears to my eyes: "But it tastes too healthy. I prefer the processed stuff."
She didn't need to convince me and for a brief shining moment every one of the 3,451 miles between us had vanished. I went to the kitchen and picked up a spoon. I turned the lid.