It's a little sensational for the headline. 72% of fourth graders are reading below expected levels. And they are blaming decades old teaching tactics, which seems odd as you would expect a larger percentage of adults not to be able to read if this was truly the problem.

I believe the concept of a meme is actually much more universal than metaphors and funny, although a majority may fall into that. It's more of a 'unit of information'. Like when a meme is using a photograph of a scene from a tv show, that moment in the show may come with a series of emotions and thoughts that are shared between people.

A metaphor comes close to it, but for everything that we consider as a meme it's not broad enough IMO.