A common mistake made by authors of fiction, in particular inexperienced authors, but even by some who are renowned, is to attribute to one of their characters something which the author – as the omniscient creator of everything in one’s imaginary fictional world – knows but which one’s character couldn’t possibly know. A similar mistake is committed by geneticists and their many imitators who attribute to living organisms a strong concern to preserve and pass on their genes.
The fact that genes are what determine the growth, development, and behaviour of all organisms is a very recent discovery. Moreover, this fact is known only by human beings. Besides our own species, there is no other species whose members are aware of the true determinants of their behaviour – not zebras, horses, dogs, snakes, leopards, frogs, birds, elephants, dolphins, whales, insects, or plants. And yet, there are numerous writers, both geneticists and otherwise, who blithely attribute this knowledge to both human beings and other organisms by declaring that an organism does this, that, or the other in order to pass on its genes to its progeny.
In the case of species that reproduce by sex, these organisms have sex not because they want to pass on their genes, but because it is pleasurable. In our own case, if it really were true that we engage in sexual intercourse in order to pass on our genes to as many children as possible, then the logical course would be never to use any kind of birth control and never to have abortions. Considering how often a typical adult engages in sexual intercourse in Western countries today, and how rarely this activity results in the birth of a child, we would have to conclude that, from the evolutionary point of view, this behaviour is an abysmal failure.
In the past, when Westerners were more devout, they usually attributed a divine cause to everything, whether good or bad, that happened in the world and in their personal lives. The advent of science provided alternative, non-religious explanations for many phenomena which previously were believed to be mysterious and inexplicable. Now, for example, instead of interpreting thunder and lightning as signs of God’s wrath, we regard these as natural phenomena that are due to large electrical discharges.
Before the discovery of the primordial importance of genes, people were only aware of their desires to do certain things, such as to eat when they feel hungry, drink when they feel thirsty, seek shelter from the cold, avoid things that cause them pain, protect themselves and those they care about when they are threatened, and copulate when they feel lusty. Of course, these desires and their accompanying behaviours are determined by our genes, since they increase our chances of survival and also the survival of our species.
That an event A produces a result B does not necessarily mean that B was the reason why A was performed. Car crashes are fairly common wherever people drive cars, but obviously no one would conclude that this is the reason why people drive cars, even though the rate of car crashes in a population is probably comparable to the rate of births in some countries. Similarly, the great majority of offspring of all kinds that are born – whether seeds, eggs, or babies – never reach the stage at which they can pass on their genes to their progeny, having been consumed by another organism before they are able to do so. And yet, no one would argue, for example, that the reason why a frog or fish lays its many hundreds of eggs is to feed all the hungry organisms that live in its vicinity, or that the reason why the almond tree produces almonds is so those greedy and selfish humans can harvest them and eat them all, or the reason why trees grow tall and wide is so they can later be cut down and turned into paper or furniture. To give an even more ludicrous example, it is a fact that every single organism that is born will eventually die; but obviously we cannot therefore conclude that the reason why we are born is so that we can later die.
The point I am making is that one should be careful when attributing a purpose to Nature. The knowledge that genes are what make us do the things we do should be used sparingly, and not in the indiscriminate and profligate manner that many writers and intellectuals are wont to use it, much as a chef who becomes infatuated with a certain ingredient and proceeds to put it in every single dish one makes. This behaviour is simply another example of the uncritical imitation of a particular model of behaviour, in this case the model of attributing all organisms’ behaviours to the desire to pass on their genes to their progeny, even though this belief not always correct.
 That this is the case is shown by the fact that if sex were suddenly to become painful, then obviously the organism would avoid having sex.
 What I mean by this comparison is that the ratio of the number of car crashes to the number of automobile trips is roughly comparable to the ratio of the number of births to the number of times that people have sex.