ThunderCats, an animated show created in the early 1980's, has recently been given a reboot; and is currently being aired under the same name on Cartoon Network.
Taking the opportunity, it is intriguing to see how the image of the role model to children and young adults has changed. There are plenty of other examples, but this revitalization of an older series, in a dramatically different way, serves to highlight the keen differences. What it basically comes down to is the shift of the 'age of idealization'. In the 1980's version, Lion-O, main character and leader of the ThunderCats, is shown as being in his prime and successful as a middle aged man. In the 2011 version, Lion-O is portrayed as a teenager, slowly coming into his own.
Where this is underlined the most is in the opening episode of the 1980's ThunderCats. Forced to leave their home planet, the cast boards a spaceship and are put in suspension for the journey to their new home. Lion-O enters as a boy of 12, but due to 'flaw' in the capsule, more than doubles his age during the journey. Thus, he bypasses puberty almost entierly, and emerges on the other side the idealized aged of an adult. Now he is recognized by the others as an authority figure, and a natural leader. (While some trials at his leadership are remarked upon, for the most part of the series Lion-O goes unquestioned. Though technically he is still a child)
Some other prime examples of heros of the era are He-Man (Who also has a 'male' symbol of a sword that he uses to banish his weakness and cowardliness by transforming from pathetic Prince Adam to He-Man) G.I. Joe, Spiderman, and Transformers. All represented as fully grown-up heros who face trails, but are for the most part set up, and issues of maturity do not arise. They are viewed as capable.
(It should be noted that the pervious transformation of the ideal hero changed the character from a perfect individual, a la Superman, to one riddled with personal flaws, in this era numerous comic heros succumbed to drug addictions. But that is another chapter)
In the new 2011 ThunderCats, Lion-O is openly acknowledged as a teenager who isn't thought to be mature enough to be leader of the ThunderCats. In fact, Tygra is seen to be a better future King. We see that, Lion-O is rash and a bit impetuous, and spends much of his time trying to prove himself to enforce his authority. That being said, slowly over a number of episodes, he proves himself of a good heart. By fate and by fortune he is forced to grow up and learn from his mistakes.
Some of 2011 Lion-O's kin are characters such as Ben-10, a younger remake of TeenTitans, Batman Beyond, and Avatar The Last Airbender. The enemies of these heros tend to be adults and are perhaps stronger or smarter than the main characters. However, the advantage of youth is their unpredictability and ingenuity. They are viewed as more flexible because they are still growing and morphing as people. These characters often have to come to terms with the ideas of responsibility and possible death of their heros as they are forced to forge their own path.
These characters are aimed at the same age group as the aforementioned heros, yet they tend to be at least 10 years younger. Either the same age as, or only a little older than the audience they are trying to appeal to. The mind set is different for these two groups of heros. Before it was seen that a hero's journey did not begin until he was an adult, and was then face with adult problems. The viewer looked up to the adult, and idealized the day when he (or she) too wielded the power of an adult. Characters of this generation are being given adult problems as children, and are told to 'grow up'. That experience of difficulty and maturity as they face all these age old problems for the first time perfectly parallels the lives of the young viewers. Giving the idea that the audience is also at an age of power, and is also capable of doing and experiencing great things.
Additionally, the rise can be seen in the explosion of Young Adult literature. Classified as marketed towards the ages of 12 to 20, YA stories are usually acknowledged as coming of age stories, where the main characters are often around the same age as the market they are trying to appeal to. A common theme is an old and decrepit society (representing the parents) that is no longer appropriate, and now must be overthrown by the youthful hero, or heroine. Some recent notables are The Harry Potter Series, His Dark Materials Trilogy, The Hunger Games Trilogy, and The Uglies Trilogy.
All this being said, I look forward to ever more young heros, what will be the focus of the next generation of heros, and how the new ThunderCats show will fair.