Stop focussing on Ps and Qs
If you have children, which approach do you favour when they forget to say thank you?
Condescension. Works well no matter the underlying emotional state. Happiness, sadness or suicidal ideation. All are masked by the nauseatingly sing-song, and only semi-rhetorical, "What do you say?".
Echoing. Commonly heard in schools, the approach requires you to over-enunciate every syllable of "Thank. You. Uncle. Arnie". Then wait for it to be repeated back to Uncle Arnie, note for note, and just as devoid of feeling.
Formality. Especially popular on birthdays and Christmases. This requires most of the money any one person has gifted to be spent on a card and postage containing written thanks for said money.
For most people I imagine it is probably a mixture. Different horses for different courses and all. Maybe make a mental note next time little Johnny takes a proffered pound coin from an elderly relative and stuffs it into the pocket of his Hollister hoodie, without a word.
Keep doing that and you can make a tally. Every time you say one or the other, you can equate it to the chip-chip-chipping away you are doing to Johnny's level of emotional intelligence and his understanding of empathy.
One day, maybe 20 or 30 years from now, you can look at little Johnny - probably calling him big Johnny by then - and see him bitterly resenting his lonely and empty life. And you can sit back and think, "I helped create that, I did."
Ok, maybe I am being a wee bit unfair.
But when is the last time you had to 'remind' your child to say thank you?
Saying or writing thank you – including, but not limited to, its brethren, thanks, cheers, ta, appreciated and the wordless simultaneous smile-and-nod-and-eye-raise – is something of a British tradition. It is as common as Eggs and Bacon, Roast Beef and Yorkshire puddings, and 5 pints of Stella and a fistfight.
To the British, remembering your Ps (pleases) and Qs (thankyous) is a way of showing you deserve your place on the moral high ground.
It shows we have been 'brung up good', as my dear old parents used to say. Dear people who were better at correcting the grammar of others than they were at using it themselves. Not saying thank you is not the same as pointing or grunting but, in many circles, its absence says something about the parents and their failure at parenthood.
This is why you still see many parents barking at their child to "SAY THANK YOU" with a tone of aggression that seems to juxtapose the display of manners they wish to encourage.
Allow me to illustrate with a particular memory from my own childhood that may resonate.