by Adam Lee on October 10, 2006

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And these words which I command you today shall be on your heart. You shall teach them thoroughly to your children, and you shall speak of them when you sit in your house and when you walk on the road, when you lie down and when you rise up. You shall bind them as a sign upon your arm, and they shall be for a reminder between your eyes. And you shall write them upon the doorposts of your house and upon your gates.

—excerpt from the Shema, a prayer that all observant Jews are required to recite twice daily

It is with some justice that philosophers such as Daniel Dennett have labeled Charles Darwin’s theory of evolution by natural selection the best idea a human being has ever had. In a single brilliant stroke, Darwin explained all of life’s vast diversity and subtle adaptation in a set of orderly, simple principles that define the means by which living things evolve to suit their environments. Few other ideas have so effectively shown the power of science’s reductionist viewpoint toward studying the world.

However, as with most important scientific ideas, evolution has undergone many modifications and extensions since it was first proposed. One implication of Darwin’s ideas which did not occur to him is that evolution is not limited to acting solely on living things and their genes. Any unit of information that is reproduced imperfectly and faces competition to survive and spread can undergo, and will undergo, an analogous process of evolution. And though it may be hard to see initially what other informational unit could participate in such a process, there are indeed other replicators out there, whizzing around us by the hundreds every day, multiplying invisibly in great swarms, and struggling against each other, often violently, for dominance. They are known as memes.

Just as the gene is the fundamental unit of biology, the meme is the fundamental unit of culture. A meme can be a word, a song, a phrase, a parable, an invention, an idea, a technique – anything that tends to be passed on as a single, cohesive unit. A single musical note is probably not a meme, but the sequence of four famous notes that make up the opening to Beethoven’s Fifth Symphony undoubtedly is. But while genes assume a relatively limited repertoire of forms – DNA, RNA, protein – memes by comparison are promiscuous in the diversity of encodings they take on. A meme can be expressed as a set of marks on paper, a set of speech patterns in the air, a set of neural firings in a brain, a set of bits in the memory of a computer, or any of the vast number of ways in which human beings communicate and express ideas.

And just as living things are ultimately made of genes, our society is largely made of memes. A human being with no memes whatsoever would be little different, intellectually, from other animals; such a person would have no language, no skills, no knowledge about the world. It is the vast pool of memes circulating in human society, independent of any single mind – what some authors refer to as “extelligence” – that has boosted humanity’s collective intellectual capacity beyond the outputs of isolated geniuses and that has made it possible for us to exert the degree of control and understanding we do over the external world. Our society is like a boiling, turbulent cauldron of memes, with some rising and some falling, some spreading as rapidly as wildfire and others fading away, as different ideas vie for available mind space.

I wrote in my essay “Thoughts in Captivity” that memes also differ from genes in that a single meme can reproduce and spread through human minds all by itself, whereas a gene must usually cooperate with other genes to build functioning organisms in order to be passed on. This is true as far as it goes, but an important point is that memes often do not travel in isolation either. Just as the selective environment that determines a gene’s success or failure is composed principally of the other genes that interact with it, so too do memes expressing similar or related concepts, memes that reinforce each other, often band together into memeplexes that reproduce more successfully than any of those memes could do on their own.

There is another subtle point that is well worth grasping. It is true that many memes have spread because they are beneficial for us, because they provide the person that possesses them with an advantage over a person who does not. Memes such as the wheel, the scientific method, or E = mc2 have thrived because they increase our knowledge of the environment and our ability to alter it to our benefit. But it does not follow that every meme behaves in this way. As per the principles of evolution, a meme cannot spread unless it confers some replicative advantage, but that advantage need not be to the meme’s carriers. On the contrary, a meme can flourish because the instructions it carries are good for the meme itself, not for the human being whose mind contains it.

For example, consider the meme of killing oneself and others in an explosive orgy of violence – a meme put into effect by school shooters and suicide terrorists alike. This meme is, sadly, replicating quite well (as recent news headlines show), despite its lethal effect on its carriers. It succeeds because the vivid media attention given to these shocking events helps it reach other troubled minds in which to take root, just as a virulent plague can afford to kill its hosts rapidly as long as it is contagious enough to jump to new ones in time.

Another example, indeed the paramount example, of memeplexes that replicate because it is advantageous to themselves to do so is, of course, religion. Religious memes have been fantastically successful at spreading through human minds, but it is not necessarily because they confer any advantage on their hosts. If anything, the vast amount of elaborate, repetitive behavior and ritual demanded by many religions, not to mention the huge investments of time and financial resources, often make religion a net drain on the people who practice it. Although religions do provide some social services to their members, that is not the only or the most important reason why they persist. Rather, religious memes persist because they contain a variety of ways to ensure their own propagation.

One of the most common is the instructions contained in religious memeplexes that say, “Teach me to your children while they are very young.” In a species that needs as much post-natal mental development as humans, there are sound evolutionary reasons why children must be willing to believe anything their parents tell them: this is how we absorb the vast quantities of information needed to survive. But religious memes, like parasites free-loading on the efforts of others, have hijacked this and turned it to their advantage. A child’s entire worldview, their most basic beliefs about what is plausible and what is not, is usually learned from their parents. Furthermore, relatively few people ever throw off the beliefs taught to them in their childhood, making the indoctrination of children a particularly effective and insidious way for religions to make converts. It is not that any individual planned this deliberately, but rather that religions which only targeted adults would probably be crowded out by religions which encourage the indoctrination of children. By the time someone becomes a potential convert to the “adult” religion, they will probably already have a religion of their own and will be much less likely to convert.

Similarly, it is no coincidence that religious memes discourage doubt and teach their followers to shun sources of information which conflict with their beliefs. Once they have gained a lock on a person’s mind, religious memes naturally will thrive by suppressing all competition. Their “aim”, in the non-anthropomorphic sense, is to convince a person who is in their power to believe in them alone and to fiercely reject all other sources of information and ways of knowing. This excerpt from an e-mail sent to me by a Christian correspondent makes this explicit:

Prior to finding the truth, which is Christ, I was open to hearing opposing views, but now having found the truth it would be pointless to waste my time. …I am absolutely 100% convinced that I have the truth, the whole truth, and nothing but the truth… I heartily echo what the Apostle Paul said in I Corinthians 2:2: For I [am] determined not to know any thing among you, save Jesus Christ, and him crucified.

In this respect, religious memes show striking similarities to the way parasites in nature subvert and control their host’s behavior. In his book Parasite Rex, Carl Zimmer writes about an especially bizarre species of parasitic barnacle, Sacculina carcini, which infects crabs. Once it has penetrated a crab’s exoskeleton, Sacculina begins a new life inside the crab’s body, sprouting a web of fleshy tendrils which infiltrate its host’s viscera and draw nutrients from its blood. An infected crab ceases growing, ceases molting, and ceases mating, as the parasite redirects all the crab’s energy towards nutrition for itself. In effect, infected crabs become zombified eating machines, consuming food only to nourish the parasite inside them.

The Christian quoted above is very much the memetic analogue of this. This person originally e-mailed me to respond to my article “Foundation of Sand“, writing that she had something she wanted me to consider. The rest of her e-mail consisted of a long list of verses cut and pasted from the Bible. When I wrote back to ask this person if she had a response to any of my actual reasons for being an atheist, she responded that she had no intention of disputing my arguments, but only felt compelled to “proclaim the gospel” to me. Following this was another list of cut-and-pasted biblical quotes, interspersed with arrogant declarations of total certainty like the above. She also declared that Jesus Christ, by which she really meant the Christian memes controlling her, was “my life, my all in all”. Like a crab controlled by Sacculina, this individual has lost all capacity for independent thought, becoming nothing more than a mindless vehicle of repetition for the memes dwelling in her head. Admittedly, this is an extreme case, but by no means a rare one.

When we see Christians mindlessly reciting Bible verses, or Jews teaching the Shema to their children on the Shema’s instructions, or Muslims blowing themselves up in suicide terrorism, we are witnessing infectious memes at work. Some of these memes are relatively slow-spreading and benign, while others have all the urgency and rapid spread of an epidemic. All of these ideas, however, are vying for space in human minds, using whatever tricks they can to shoulder aside the many others that are doing the same thing. But in this war of the memes, the one thing that every one of them is lacking is any evidence at all that they originally came from, or are sustained by, anything outside the efforts of human minds.

Fortunately, there is an antidote to all these infectious religious memes. We atheists have the antidote – in fact, we are the antidote. And we have made great strides in spreading our own message and setting many people free from the tyranny of warring memes, but not nearly enough. The only question is whether we can organize and focus our efforts effectively enough to truly bring enlightenment to humanity and sweep away the otherwise endless battles of faith and superstition.