I think animals having conscious experience seems a reasonable opinion. Many animals display a lot of behaviours we have in common with them, they have similar senses, similar emotional responses, similar social behaviours, even similar reasoning abilities in a lot of contexts. Tye brain regions with activity associated with these behaviours correspond to equivalent regions in our brains.

Its true we have additional brain structures responsible for higher reasoning and linguistic abilities that other animals don’t share, but it seems likely that these features are layered on top of those other capabilities we inherited from our common ancestors with other mammals.

In support of this, there are some behaviours we share with other animals that are not conscious, or at least that are so automatic that we are essentially mere observers of our own behaviour. This includes many instinctive behaviours, and these are often shared with lower order animals that do not display sophisticated awareness of their own existence and that of others. It seems reasonable that we inherited those behaviours from common ancestors with such animals (lizards, frogs, etc) before self consciousness evolved.

> The human anxiety about animal suffering needs arguments to support it

You want arguments supporting that humans dislike seeing animals suffer? To most people that would be obvious, I'm not sure what to say.

No, that's not what I meant. I'm saying that reasoning from anxiety is not valid.

It is valid, we are talking about what humans thinks, not what is true. If humans thinks animals are conscious then they think animals are conscious, doesn't mean animals actually are conscious.

And the fact that I don't get downvoted here is evidence people here also think that animals are conscious, which supports my argument that people think animals are conscious.

Oh, OK. I think that the "because animals are conscious" part is only retro-fitted to the "don't make animals suffer (because I don't like it)" argument. I think it's a somewhat disingenuous post-hoc justification, but people convince themselves of it. So in a sense, yes, they think animals are conscious: most people will readily take this argument out, parade it around, and sometimes they do science that's supposed to relate to it, or refer to that science and think and worry about the argument ... but I still think it arises from mere justification of a feeling and is essentially hollow and therefore (breathe) although people say they see animals as conscious, they aren't really meaningfully looking because they already decided in advance, and it's not really sincere thought that they put into it. But this is just, like, my opinion.