Since my last sortie across the Atlantic, cars have become smaller and Americans have grown bigger. This melting pot of nations and races has produced a hybrid of humanity with all the vigour of its diverse genetic pool. The average height is taller than here, aptly illustrated by the muscular frame of cousin Paul towering over his diminutive kinswoman, Mrs Sweeney.
A US television documentary highlighted the distressing problem of child obesity, with an alarming proportion of young people categorised as extremely overweight. This trend is evident on pavements, at baseball games and in eating places as the nation's youth graze incessantly on fat-laden burgers and high calorie crisps. Portions are gargantuan.
I am reminded that a small number of my own charges in Holy Rood could be considered unhealthily obese and that the social mores which have created the American epidemic are prevalent in Edinburgh as well as New York.
The issue of child obesity preoccupies the purveyors of psychobabble that is American television. From dawn to dusk, in a seamless tapestry of chat shows, families bare their souls on matters social, sexual and psychological to ostensibly empathetic presenters as voyeuristic audiences bay for more succulent details. These toe-curlingly intrusive encounters have a vernacular and vocabulary of their own. "I am hearing that you need to reconfigure your priorities," offers the suave Montel, as the hapless victim is outed as a juvenile delinquent or unfaithful spouse.
However, one presenter's assertion about ageing that "just because there's a little snow on the roof doesn't mean there's no fire in the furnace" did strike a personal chord.
We saw George "Dubya" Bush, and Old George too, embarking on a fishing trip at Kennebunk, Maine. I wanted to ask him about charter schools, which he has wholeheartedly supported since his accession to the presidency.
These schools are given a high degree of autonomy, often with support from local business, but remain accountable to the state government for their finances and academic progress. Many seemed, from news reports, to be struggling to survive because of spiralling debts.
Needless to say, a burly entourage of security staff with bulging pockets ensured that nobody got within chatting distance of George "Dubya" or his Dad.
A teacher we met from Pennsylvania enquired: "Do you work in a standards-driven school?" "Oh yes!" I assured her, "Definitely standards-driven." When I explored what she understood by this, she explained: "It really means that you have a heap of paper for each kid. You have to send one sheet of results here, another there and it leaves you no time to teach." I was able to advise her that such fruitless paper-chasing was entirely unfamiliar to the Scottish teacher.
Cousin-in-law Caroline from New Jersey considered a career in teaching but a stint as a substitute - supply - teacher had irrevocably eradicated any such aspirations. The lot of the supply teacher is universally challenging.
Caroline persuaded me to participate in the Morgan Chase Corporate Challenge, in which 2,500 runners of all ages and backgrounds competed for charity over a 5km course. I was privileged to take the place of injured Doug Rex, who suffers from muscular dystrophy and who regularly takes part in races, with jovial disregard for his disability and the slowish times he clocks.
These were a very hot few miles, made tolerable by local children who turned out in their hundreds to spray the passing runners with outsize water guns. It was a memorable occasion and Doug Rex was an impressive individual. Long may he run.
Before the homeward journey, we purchased a compact disc, shockingly entitled Alice in Chains, as requested by nephew Martin. Auntie May ruefully wondered what had become of Winnie the Pooh and Thomas the Tank Engine, his preferences of yesteryear.
Pat Sweeney is headteacher at Holy Rood High School, Edinburgh