or indeed any letters at all...
I come from a tradition where if you got a present you wrote a nice handwritten thankyou that showed you appreciated the thought and consideration of the other person. I've always tried to stick to that because I think that particularly with aged relatives, most gifts are about thought and consideration - and surely a little piece of nice warm fuzziness from the other person to you, deserves a nice warm fuzzy back, in whatever form will make the other person feel properly pleased. With rellies over 70 that is generally a thankyou letter. While it was often a struggle with my grandparents, I always tried to treat older generations as people I could and should relate to as normal humans.
DP comes from a tradition where that is seen as ridiculous hyper-social manneredness from the stunted 1950s when women were stuck in the home scrubbing and washing children. His parents have the convenient arrangement that because his father earns squillions and is rich anyway, his mother gets to not have a full-time job, lead her own life, pay for babysitters for the kids a lot (in the past), be "feminist" about doing only stuff that suits her (some of it is very sensible, eg having a fulfilling career even if it isn't a very good earner or full time; however some of it is really silly).
DP's parents have brought up their kids to not ever have conversations with adult guests, to tell grandma what they're doing at school and not wait for an answer before disappearing, to have no interest in interacting with older generations (to the extent that they don't know they still sound like schoolkids in their 30s), and most importantly to this thread, to never acknowledge presents from people (or say thankyou for having us over to dinner, or whatever) because apparently that just gets into a cycle of "thankyou for the thankyou" type letters.
This all seems to be a reaction to DP's mother's rather 1950s upbringing, most which she firmly dismissed as soon as she was the first one in her family to go to university and discover life beyond the kitchen. So you can see why she's still reacting even 40 years later, but I find the cumulative effect on her kids pretty sad.
I write those kinds of thankyou for the thankyou letters to my aunts and great-aunts all the time - because I write to them fairly frequently anyway, because (1) it's fun to correspond with nice people (2) they're interesting and (3) I feel a bit sad that noone else in my family pays them much attention.
I am increasingly feeling despondent that DP won't write thankyous to my family or his own, or interact as a human (rather than a disinterested schoolkid) with anyone of an older generation. My aunt has just knitted him 3 awesome jumpers - which are lovely - and his reception of them was that he wouldn't wear them outside the house and yes he might write her a letter but he's too busy right now (which is a translation of "no I won't", every single time). They'd be fine for him to wear to work, given what other people at his work wear.
My parents have stopped giving him presents, and my sister has started giving him Oxfam goats and nothing else, because of this total lack of acknowledgement, but he hasn't taken the hint.
I'd be sad if people said "he's a tool, leave him, bastard"... but I really don't know what to do about it. I think it's utterly mannerless in a bad way, he thinks it's throwing off the shackles of the 1950s because his Mum says so.
GRR.