Ever since they began, superheroes have always had a secret identity, a means to relax and get away from their responsibilities as heroes. Many heroes will use their civilian identity to attempt to live a normal life, while also protecting the people around them from immediate danger from their double life. Each hero has their own way of doing this. Some wear masks, some physically transform and others adopt completely different mannerisms to back up the ruse. A secret identity, and the double life that goes along with it, is one of the most basic superhero tropes, but the MCU has a different approach.
Interestingly, in the MCU, the idea of a secret identity is not really touched upon. At the end of Iron Man, Tony Stark reveals to the world that he is Iron Man at a press conference. Everybody knows Steve Rogers is Captain America - he has a museum exhibit in his honour for god's sake! Thor is just Thor, he uses the Donald Blake alter ego as an easter egg. The army are well aware of Bruce Banner being the Hulk. Though the world doesn't know who Ant-Man or Spider-Man are (yet), it will be interesting to see how they approach this in the upcoming films... Especially if Civil War follows the comic story faithfully.
Why Have a Secret Identity?
Being a superhero is incredibly dangerous work. As superheroes, they will make many enemies in their double life. A secret identity means that superheroes can get away from enemies and lead a normal life, while also protecting their loved ones. Superheroes will often have a number of close friends and family in their supporting cast and they will often not reveal their double life to them to keep them from danger.
A villain learning a superhero's secret identity can have drastic consequences for that hero. This is most obviously demonstrated when the Green Goblin learns that Peter Parker is Spider-Man. The Goblin kidnaps Peter's girlfriend, Gwen Stacy, with devastating consequences. The death of Gwen Stacy was the first time a superhero had truly failed outside of an origin story and it all came from the villain learning his identity.
When Tony Stark reveals himself to the world, he immediately endangers those closest to him. He also makes himself a prime target. Stark is a well known public figure anyway and his armour inspires many imitations. Justin Hammer wishes to create an army of replica Iron Man suits and sell them to highest bidder in Iron Man 2. But Ivan Vanko (a scientist whose father was wronged by Stark) decides to use his knowledge to sabotage them. A similar thing happens in Iron Man 3, as Aldrich Killian was wronged by Stark and chooses to attack him where he is most vulnerable. Killian kidnaps Pepper Potts and injects her with the Extremis serum. Had Stark's identity not been public knowledge, Pepper could have been safe from harm.
Why it Makes Sense...
It does make sense that Marvel choose to forgo secret identities in the MCU. Look at Steve Rogers, a man with his achievements in the war would certainly have been celebrated and remembered. After his disappearance, the world assumed Captain America was dead, so why would they need to keep his identity a secret? Nobody knew that 70 years later, he would be discovered frozen in the arctic and then revived to save the world once more. The exhibit in the Smithsonian museum celebrates the greatest hero of World War 2 and, rightly, tells the full story of Cap's journey from a scrawny young man into the legend he would become.
Thor is another example. As an alien "god" with power over lightning, he does not need a civilian identity. In the MCU, after his trips to Midgard (Earth) he returns to Asgard and, as a warrior prince, fight wars and celebrate victories with his companions. There is no need for his Donald Blake identity. Though he is banished from Asgard in Thor, he returns a hero by saving Asgard from Loki's reign of terror. This is different to the comics where he is banished and stripped of his godlike powers until he proves himself worthy. This is where Donald Blake comes in. He is a surgeon who stumbles across Mjolnir and his powers are returned.
Are Secret Identities Outdated?
We live in a world where everything is instant. Twitter allows us to share opinions on anything immediately. News breaks as it happens, whatever time of day. As the MCU takes place (mainly) within the present timeframe, this must also be true there. If a man with wings flew past a window, you could safely say there would be pictures of him all across social media. This would make it extremely difficult for that man to maintain his anonymity, unless of course he was wearing a mask. As I mentioned earlier, Ant-Man's identity is not yet public knowledge and Spider-Man has yet to be introduced, but both of these men wear masks. It would be much easier to conceal themselves because of this.
But that is not to say that Civil War will not follow the comics and have Spider-Man, among others, reveal his identity. I feel that the secret identity is a big part of superhero stories and it is an area Marvel could be missing out on. However, I can also understand that the world we live in now would make it very difficult to conceal a hero's identity. What do you think, should Marvel have kept their hero's identities secret, or have they made the right call in revealing them to the world?