There are two senses in which to consider the phrase.

The sense in which memes enter or exit our minds. The sorts of behavior encouraged by our memes.

For those who don’t know what I’m talking about:

A meme ( meem)[1] is “an idea, behavior, or style that spreads from person to person within a culture”.

Richard Dawkins introduced the idea in his famous book: The Selfish Gene. The bulk of his book discusses examining the gene as the basic unit of analysis in evolutionary studies. He introduces the idea of the meme as a different form of replicator. Both genes and memes will only be reflected in the outcome of biological and cultural evolution if they exhibit fitness–if they are able to survive.

So the cultural traditions that helped hunter-gatherer societies survive droughts or harsh winters tended to survive and spread. Over time a culture accumulates this sort of practical, tacit knowledge. (Side note: this week’s Econtalk has Cesar Hidalgo who does really interesting work trying to indirectly measure the presence of such tacit knowledge in market economies.) And if culture is made up of memes, the same way organisms are made up of genes.

Looking at genes as the unit of analysis (as opposed to the organism) explains some otherwise mysterious behavior. It provides a plausible explanation of altruism: we care for our children more than anyone because 50% of their genes are our genes. A nephew is still precious, but not as important to us because the expected ratio of shared genes between the two of you is 25%. A gene that prompts you to protect your children is likely to survive longer than a gene that doesn’t prompt you. (And genes that hang around with such kin-protects genes are also more fit than their competition.) A gene that prompted you to be kind to neighbors makes sense when you live in small groups. But a gene that prompted you to be kind to total strangers might be a liability in a world where strangers were dangerous.

Cultural evolution certainly makes sense as a gradual mutation of different cultural practices merging together to make what is called (and perceived) as a unique body of culture. It’s a complex of knowledge, ideas and basic assumptions, social interface protocols, and it’s deeply embedded in how we engage in the world. (Perhaps we can’t remember our infancy because we didn’t have a cultural lens through which to reference anything to anything else…) One thing that I’m sure we’ve all noticed is that it can be almost painful to have to reject a cherished belief. It’s even difficult to see one of these memes challenged.

Now genes don’t have to be small bits of genetic code. They can be something simple like “make this enzyme when you get a chance.” But as a unit of replication, you should consider the smallest discrete chunk of genetic coding that replicates itself. If a particular pattern isn’t fit, it will leave the gene pool, while the fit collections of genetic instruction spread. So you might end up with long complex strings of genetic material akin to a computer program. Initially simple scripts might gather as successful collections of genes that work well together. The “produce stomach acid” gene works well with the “produce a stomach” gene and soon the two are virtually inseparable. They’ve become a simple script: “Do this, then that, then maybe this other thing.” Scripts gather into multi-cellular organisms with different functions that can respond differently to different stimuli. Soon you’ve got a complex set of code as your replicating unit.

More complex genes are necessary to prompt more complex behavior. It’s worth noting that Dawkin’s theoretical framework sometimes looks like a hyper-rational economics model. Evolutionary Stable Strategies are a Nash Equilibria that are robust to invaders. They occupy a niche and survive. But this evolution is happening in the context of increasing complexity. The system is learning*. This isn’t an instantaneous process**, but it is gradually becoming more sophisticated.

A complex gene will get bugs due to random mutation, but as long as it’s still generally fit, it will survive. And over time, more subtle and sophisticated programs identify new niches. And we get plant genes surviving by filling the “eat sunlight” niche and animals in the “eat plants” niche, and bacteria co-evolving with animals’ digestive systems.

Slowly working through this long, blind, random process genes surviving this hostile environment develop behaviors that help them flourish (the “four F’s of evolution: Fighting, fleeing, feeding, and reproduction”). Gradually they stumble into opportunities, and an important one was social behavior.

More and more complexity, round and round, until we start to get our first little bits of sentience. I’ve been watching a chinchilla hop around my apartment for a couple weeks now and I’m astonished by how much effort she puts into genuinely exploring her world. She tests objects for structural integrity and learns what she can and can’t jump on. She tests boxes with her teeth, I don’t know what for. She’s distinctly learning and not merely existing or surviving. She’s comfortable and does not know fear (I’ve seen her scare one particularly wussy cat). That sort of behavior requires a great deal of complexity which requires a great deal of genetic material.

I’m noticing as I write this that the biggest gene (i.e. discrete, replicated set of genetic code) must be that very large collection of genetic patterns that must come together in order for a one’s offspring to simply be the same species.*** I’ve heard that humans and chimps share 94 percent of our genetic material. That overlap tells me that some larger percentage than that is what makes us actually a human. The difference between any two individuals, then, must be among a very small portion of their total genetic makeup. This small portion is where genetic competition occurs in the arena of sexual reproduction.

In any case, our first memes (behaviors) seem to be transmitted biologically. Later, with more complex genes, we are able to replicate more complex behaviors. Eventually, we get complex enough to build up a sense of consciousness****.

A complex enough gene might have a subroutine that sets off an error; something like the pain our consciousness experiences when things are going poorly*. And likewise for a meme. Though more likely is that the error is being returned by our psychology. (If our genes are assembly language, our psychology is the operating system, and culture is the mess of basic programs that makeup our desktop environment.)

When we think of memes as self-replicating units, interesting questions arise: what sort of patterns will be robust to competition? Which will occupy what niches? What happens when incompatible memes come together in one mind? What sort of eusocial behaviors are possible? How much do our memes govern our behavior? (This is where nature and nurture overlap.)

Obviously one possibility is a “selfishness meme,” or a culture that hits an equilibrium of distrust. But there are many others, and how they combine matters. At this level we’re essentially asking questions about psychology, culture, and institutions. The fodder of all the social sciences comes together here. Different memes will be transmitted in different ways (which is perhaps what defines the disciplines), but any of these memes may be complex enough to have a defense mechanism that involves activating various processes (including other memes, perhaps) and perhaps making people feel anger and related emotions when someone questions our beliefs and may even push people to fight with their life for their memes.

*We’re computers, markets are computers, societies are computers, the ecosystem is a computer, Earth is just a big giant computer. It processes data and creates new data.

** The next Hayek rap should include the phrase “it’s spontaneous order, not instantaneous…”

*** I could imagine it as made up of some set of smaller genes in some complex, rather than one monolithic gene but I don’t have the language to communicate that idea concisely.

**** And it must be noted that this consciousness is built out of parts designed for the poop-and-panic machines that were our evolutionary ancestors. It’s like building a super computer* out of a truck load of Pez dispensers and a warehouse full of chainsaws. And yet, how else could it be done.