Iron Man is intelligent, but Thanos is smarter than Iron Man could ever be. He learned things as a child that Iron Man still couldn't understand and knows secrets about the universe that no one else knows. If he set out to, he could create a suit of armor much more powerful than anything Iron Man could imagine.
In a single scene in Infinity War, Shuri proves that she's smarter than Bruce, and the rest of her work proves that she's got the edge over Tony more generally. Of course, it helps that she grew up in a virtual tech utopia. But Shuri would be one of the smartest people in the MCU regardless of where she's from.
Hulk and Banner are two distinct entities. Banner remaining inside of Hulk doesn't change Hulk's IQ. Which Hulk? If we're talking Savage Hulk, I'd put his IQ right around 99 on the Current “Wechsler IQ Classification” scale.
When it comes to the smartest Avenger, it has to be Iron-Man that is considered to be the most intelligent. While he and Bruce Banner are likely on a level when it comes to their scientific knowledge, the fact that he retains that when turning into Iron-Man just edges him above the big green guy.
TL;DR - Two different types of intelligence. Intelligence isn't a zero-sum game. Tony is obviously a genius scientist/engineer, and Bruce Wayne is a genius tactician/strategist. They both dabble in both but are clearly better at those individual aspects than the other.
Batman is universally hailed as the smartest man in D.C. Comics, with Lex Luthor his only real competition. Iron Man, by contrast, is at least the fifth or sixth smartest character in the Marvel universe, with Richards, Victor Von Doom, Bruce Banner and Hank Pym all believed to be more intelligent.
In the comics his intelligence was artificially enhanced while in his mothers womb with Kree technology. It enhanced his intelligence some, but more importantly in gave him the ability to multitask better than any human on the planet. Also it helps to have smart and rich parents.
While he's known for his powers, he's also one of the most intelligent, crafty beings in the universe. He's outsmarted gods, the Elders of the Universe, and cosmic beings. Batman is good but Thanos is out of his league. Thanos is smarter than Batman and, most importantly, a lot craftier.
Early life. Thanos was born approximately 1,000 years ago on the planet Titan to A'Lars, along with his brother Eros. Thanos deems the growth of Titan's population to be unsustainable, so he proposes to arbitrarily kill half of Titan's population.
1. William James Sidis – IQ Score: Estimated 250-300. Now, let's shine the spotlight on William James Sidis, an American child prodigy born in 1898. His estimated IQ score ranges from an astonishing 250 to 300.
Batman is highly trained in fighting and it is something that Iron Man just can't match him with, no matter how hard he tries. While both men have plenty of gadgets, sometimes a good old-fashioned fight is what's needed, which Batman would dominate.
1. Reed Richards - Mr Fantastic. The smartest man on ANY world, Reed Richards aka Mister Fantastic, has mastered time, space, interdimensional travel, and practically every other science known to man, as well as several that aren't.
Superman is smarter in a processing manner, Batman is smarter in a decisive manner. Smart can mean alot of things. And yes, Superman is smarter than Batman in certain ways, but Batman overall is better at using his smarts more efficiently.
It's not too surprising that Doctor Doom is Tony's intellectual better. With the reveal that Tony's gift actually made Reed Richards dumber, it makes sense that Mister Fantastic nemesis would be in a similar league and have an edge on even the Iron God when it comes to genius.
They are both brilliant characters. Both with mechanical skills. I would say that Tony Stark does far more tinkering with and creating mechanical inventions, but the overall genius of Lex Luther is greater. More far reaching in depth of knowledge about more than just mechanical things.
While Steve Rogers gets the title of the oldest human avenger, Thor Odinson, as the mighty Asgardian God of Thunder, has a much longer life span than any of his Earth-born friends.
In the Marvel Cinematic Universe (MCU), the title of “weakest Avenger” is subjective and can vary based on individual perspectives. However, if we consider powers and abilities, Hawkeye (Clint Barton) often stands out as the least superpowered Avenger.
