Hume wrote about how perceived similarity is a factor of empathy, for example, a human cannot relate to a piece of string.

The piece of string.

@selzero alt: a piece of string stands vertically on a card. It is kept in tension by five bits of clear plastic bent into hoops, overlapping one with the next. The card has part of a logo visible, maybe Alstom. Text overlaid on the image says "the string wants to collapse but constant stress won't allow that".

@selzero my girlfriend and I were taking the stems off green beans. I found two green beans sharing the same stem and said "that's us". How could it have this effect on her if the thing has to be human for us to empathize?

Another example, young children and their toys.

@selzero Human empathy extends to all things, literally things. We strap knives to roombas and collect little rocks and call them friends.
I don't hang around folks who don't have at least a little sympathy or empathy for things and other living beings.
We all break under constant stress, just like the string. I feel for it
@selzero I know this is a shitpost but it really highlights how this "perceived similarity" can very much be a function of language.