But memes also have a serious side, according to researchers looking at modern forms of communication. They are a language in themselves, with a capacity to transcend cultures and construct collective identities between people. These sharable visual jokes can also be powerful tools for self-expression, connection, social influence and even political subversion.
Internet memes "are one of the clearest manifestations of the fact there is such a thing as digital culture", says Paolo Gerbaudo, a reader in digital politics and director of the Centre for Digital Culture at Kings College London.
Gerbaudo describes memes as a "sort of a ready-made language with many kinds of stereotypes, symbols, situations. A palette that people can use, much like emojis, in a way, to convey a certain content".
"We see the replication of mundane reality in many forms of art," says Idil Galip, a doctoral researcher at the University of Edinburgh, and founder of the Meme Studies Research Network. "Even going back to, let's say, Hellenic times, you've got something like tragic theatre, that takes things that happen to you that are upsetting and real-life and makes them into comedic things, which is what memes do."
With the arrival of the internet, however, memes have become a more tangible phenomenon that can be observed as they grow, spread and mutate. "In a way, it's like internet users paving the way for academics to look at memes more scientifically," says Limor Shifman, a professor of communication at the Hebrew University of Jerusalem. Researchers at Facebook showed in a study in 2014 just how widely memes posted on the social media site can spread and evolve. In one example, they found 121,605 different variants of one particular meme posted across 1.14 million status updates.
Shifman's definition of memes, now widely used in the field, describes them as "a group of texts with shared characteristics, with a shared core of content, form, and stance". Broadly, "content" refers to ideas and ideologies, while "form" to our sensory experiences such as audio or visual, and "stance" to the tone or style, structures for participation, and communicative functions of the meme.
Memes tap into collective consciousness online and have been referred to as digital folklore – or "Netlore". "We can see not just the new ways people do things or the new ways people express themselves in public but also some of the themes, some of the anxieties or desires people have. All of these complex issues are reflected in things like memes," says Gerbaudo.
But for an idea to become a meme, it needs to be shared. Most successful internet memes – in that they spread wide and far – share a few key attributes.
"Usually the most viral, most loved memes are memes that are about things that are very recent in public memory," says Galip. But often they are also "something that was important to many people", she says. "Viral memes usually appeal to the most common denominator. So you don't have to necessarily be embedded in internet subculture to understand what it's saying. And the final thing I think is, it's the most basic thing but it's very hard to replicate, is that it should be fun to look at, and fun to share."
Memes also have an uncanny way of capturing a feeling, experience, or state of mind which resonates with people, depending on the "niche-ness" of the meme. One small recent study found that people with depression rated depression-related memes as more humorous, relatable and shareable. The researchers suggest memes elegantly portray the experience of depression which some may find hard to vocalise. And because they are highly relatable among people with depression, they could offer the perception of social support and emotional connection. The findings echo those in other studies that have suggested internet memes can contribute to the formation of a collective identity among marginalised groups such as the LGBTQ+ community or among disparate networks of people, such as those who have been conceived with donated sperm or eggs.
"Niche memes are not meant to go viral," says Galip. "They're meant usually to create things like in-group belonging, something that kind of strengthens a sense of identity."
One perspective put forward by Joshua Nieubuurt, who studies misinformation and disinformation at the University of Maryland in the US and the University of Okinawa in Japan, is that memes can be regarded as a modern digital equivalent of the propaganda leaflet. He points to the way memes have been used to support or undermine arguments for Covid-19 restrictions and vaccinations, using humour and sarcasm to delegitimise the stances of people on either side of the debate.
Online, memes are important facilitators of communication, belonging, and digital activism, that can both unite and divide us, depending on who we are and how we participate with them.
"This format of communication is here to stay because it's a very stable way of expressing your individuality and your communality," says Shifman. Gerbaudo notes that memes are already evolving – branching out more into video sharing. "TikTok videos are memetic in character," he says. "They respond to challenges, which have a certain format, where people need to kind of play with a given, pre-established set of interactions."