When it comes to language, I'd divide into two categories, animals using human language and animals using their own language.
In the first category, several animals have learned human languages to a certain extent. Some notable examples would be Alex the African grey parrot who learned to understand and speak English. He only had a vocabulary of around 100 words but showed conceptual understanding. Then Koko the gorilla was taught to use sign language and had a vocabulary of 1000 signs and understood 2000 English words. Chaser the border collie is another example which was covered here on Flayrah (https://www.flayrah.com/3380/chaser-learns-1000-words). She knew over 1000 words, understood nouns as categories, showed inferential reasoning (really neat video of her with Neil de Grasse Tyson https://www.youtube.com/watch?v=omaHv5sxiFI) and all sorts of cool things. There's even commercial products (https://fluent.pet/) to help pets communicate and there will be future studies on whether they are scientifically valid.
It's not just learning human languages, there's evidence that some animals may have their own versions. I mentioned that dolphins seem to have names which they can use to address specific individuals and bats actually have quite complex communication and researchers were able to listen to the recordings and learn who was saying something, what the context was, who it was directed at and what the response would be. So there's a lot of specific information in a bat's chirp.
Culture is essentially a learned behaviour which is then transmitted in a group. It's different from instinct and it becomes specific to a group, so it's purely environmentally determined. It was covered here on Flayrah with a group of dolphins that were sponges in a unique way and teaching it to members of their pod (https://www.flayrah.com/3607/dolphins-show-both-tool-use-and-culture). The other example I used in my talk concerned bonobos. Briefly, there were two groups that interbred and lived in overlapping areas but they group-specific hunting behaviours which fit the definition of culture.
I don't think any countries base personhood on language or culture specifically. I doubt any have actually made any particular attempt to define it at all. It's more a case of humans are persons and there's been an assumption that other animals are just not. There's an unfortunate history of disregarding animals as though they are mindless and sometimes they are treated as objects in the legal system. That's been improving but we've hardly fixed all the issues.
"If all mankind minus one, were of one opinion, and only one person were of the contrary opinion, mankind would be no more justified in silencing that one person, than he, if he had the power, would be justified in silencing mankind."
~John Stuart Mill~
Aww, if you're asking that it means you didn't listen to my talk from earlier in the year (https://www.youtube.com/watch?v=-2CfoBqzu00). I discussed some examples there.
When it comes to language, I'd divide into two categories, animals using human language and animals using their own language.
In the first category, several animals have learned human languages to a certain extent. Some notable examples would be Alex the African grey parrot who learned to understand and speak English. He only had a vocabulary of around 100 words but showed conceptual understanding. Then Koko the gorilla was taught to use sign language and had a vocabulary of 1000 signs and understood 2000 English words. Chaser the border collie is another example which was covered here on Flayrah (https://www.flayrah.com/3380/chaser-learns-1000-words). She knew over 1000 words, understood nouns as categories, showed inferential reasoning (really neat video of her with Neil de Grasse Tyson https://www.youtube.com/watch?v=omaHv5sxiFI) and all sorts of cool things. There's even commercial products (https://fluent.pet/) to help pets communicate and there will be future studies on whether they are scientifically valid.
It's not just learning human languages, there's evidence that some animals may have their own versions. I mentioned that dolphins seem to have names which they can use to address specific individuals and bats actually have quite complex communication and researchers were able to listen to the recordings and learn who was saying something, what the context was, who it was directed at and what the response would be. So there's a lot of specific information in a bat's chirp.
Culture is essentially a learned behaviour which is then transmitted in a group. It's different from instinct and it becomes specific to a group, so it's purely environmentally determined. It was covered here on Flayrah with a group of dolphins that were sponges in a unique way and teaching it to members of their pod (https://www.flayrah.com/3607/dolphins-show-both-tool-use-and-culture). The other example I used in my talk concerned bonobos. Briefly, there were two groups that interbred and lived in overlapping areas but they group-specific hunting behaviours which fit the definition of culture.
I don't think any countries base personhood on language or culture specifically. I doubt any have actually made any particular attempt to define it at all. It's more a case of humans are persons and there's been an assumption that other animals are just not. There's an unfortunate history of disregarding animals as though they are mindless and sometimes they are treated as objects in the legal system. That's been improving but we've hardly fixed all the issues.
"If all mankind minus one, were of one opinion, and only one person were of the contrary opinion, mankind would be no more justified in silencing that one person, than he, if he had the power, would be justified in silencing mankind."
~John Stuart Mill~