It's human nature to think they are superior to anyone and anything.
It used to be that the difference between humans and animals was one is self-aware, the other is not. Then science has proven that to be untrue and humans craved for other reasons to distinct themselves from their animal origin, which one by one are disproved as well.
Claiming something that hasn't been proven beyond a doubt to be true doesn't make it true. It's a thesis that could work out either way. There are plenty of humans that think with a firm believe that earth is the only planet in the universe with life on it. Then there are scientists that think living organisms need water to exist, despite there being organisms on this very planet for which that does not hold true. Water is required for life the way we know it to develop. Outright dismissing it as the only option is a sign of ignorance, not intelligence. The first counter-example would be Artificial General Intelligence, which is estimated to arrive within the next three decades.
Dismissing the possibility of something outright because it doesn't fit into ones thesis or world-view is a sign of ignorance, not intelligence.
It is impossible to transmit speech electrically. The 'telephone' is as mythical as the unicorn. Professor Johann Christian Poggendorrf, Germany physicist and chemist, 1860