I think the scientific consensus for cognition and brain size has been for a long time that the size matters much less than we previously thought. For instance, ravens/crows show remarkable problem solving skills and intelligence on par with much larger animals and their brains are extremely small.
Given how much meat we as a society consume, and how we treat animals generally, it makes sense that we'd collectively accept and yearn for a narrative that animals are dumb. I think science is steadily showing that this is not really the case.
Anyone who's ever interacted with any kind of animal knows how they are intelligent.
The lack of science on this matter is not the reason we still consume meat and more science won't change anything.
We've always found ways to justify/accept our need for meat and wel'll continue doing this as long as science doesn't find an equally nutritious alternative that can be produced at scale.
But chickens have a social order, keepers say, and more complex behaviour than a naive city slicker might expect. They may not be grandmasters, but they aren't completely stupid.
Sorry, I wasn't really arguing against you. It's just that every time an article like this comes out everyone act likes it's a step towards abandoning meat. Unfortunately that's not so easy.
Given how much meat we as a society consume, and how we treat animals generally, it makes sense that we'd collectively accept and yearn for a narrative that animals are dumb. I think science is steadily showing that this is not really the case.