Superheroes as barometers: The London Times examines the shift in tone of superhero films, from the sincerity of Superman to the nihilism of Batman to the sensitivity of Spider-Man:

"Superheroes make excellent barometers of the national psyche. They are walking/flying/climbing metaphors, hybrids that take the lowest or most inhuman element in man — mechanical powers, his animal nature — and pit them against his highest: a sense of sacrifice and duty. The result is a fertile one-man battleground of moral growth, enhanced by the demands of maintaining a secret identity.

"The modern superhero is a being with immense power, struggling to assert his better nature. It is not hard to see why this character holds so much appeal for American viewers as they grow increasingly uneasy at their country’s reputation around the world."