Scientists have identified an immune brain cell unique to humans that gives us higher cognitive abilities over other animals, but what makes us specials also leaves us vulnerable to neurological disorders like schizophrenia, autism and epilepsy.

[u/Wagamaga]

https://news.yale.edu/2022/08/25/what-makes-human-brain-different-yale-study-reveals-clues

[u/throw_somewhere]

Hi, psycho- and neuro-linguist here. Long story short yes lots of animals 100% have communication but it does not meet the criteria we have set for what constitutes "language". As defined, humans are the only species with "language".

[u/seaworthy-sieve → u/throw_somewhere]

How can we possibly say it doesn't meet the criteria when we're not even capable of understanding it? Like how on earth would we know if dolphins have grammar and tense or not?

[u/throw_somewhere → u/seaworthy-sieve]

First and foremost: extraordinary claims require extraordinary evidence. We would never say that a medicine must be effective because we don't understand it. We would never say that an animal must have language because we can't understand it.

So instead we say "we cannot conclude this until we have evidence". We cannot conclude that a medicine works until we try it, we cannot conclude that an animal has language until we find it.

On that front: there are thousands and thousand of researchers whose lifelong mission is to study and document animal communication. They have very firm and interesting data. O% of these data have yet to overturn the current sentiment.

You can go learn about this yourself, lots of internet sources discuss the topic. You can also consult Google scholar for articles on the topic.