Evolution of Kinship

Evolution of Kinship

Lyle Steadman

Department of Anthropology

Arizona State University

Submitted for presentation to:=

Human Behavior and Evolution Society Meeting

Austin, Texas

June, 2005

(Not delivered)

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About 150 years ago, Charles Darwin made the most important discovery ever made in biology: He came to realize that every inheritable trait of every living th= ing was subject to what he called “selection”. That is, when any inheritable trai= t – which refers to behavioral as well as physical features—would help an individual leave descendants that trait would tend to increase in frequency, along with his or her descendants. Any trait that did not help leave descendants would tend to die out&= #8212;to disappear. Because new inheri= table traits appear from time to time, when they happened to help individuals to leave descendants they ALSO would tend to increase in frequency and replace traits that didn’t help so much.&nbs= p; The discovery of this process, which Darwin called either natural or sexual selection, is recognized today as the fundamental cause of evolution: individuals in one species leaving descendants that gradually come to be in another species. This process= , of course, can happen along several descendant lines, leading to several new co-existing species.

While this discovery is seen by some today as being as significant as Newton̵= 7;s and Einstein’s discoveries in physics, it nevertheless took more than= 100 years before biologists actually began to apply this discovery to explain t= he existence of widespread traits, including behavioral traits—why, for example, males in almost every species eagerly pursue females, while females are coy and choosy.

As a biological species, humans too are subject to Darwinian selection: every trait of every organism depends on particular genes, which, by being inheritable, are subject to selection.&nbs= p; That means that all traits influence their own frequency in later generations. But humans are distinguished from other species by their great number of traditions, which= has led social scientists to conclude that genes are not particularly significa= nt to humans and therefore that Darwinian selection is irrelevant to humans. But traditional behavior, like eve= ry trait, is also subject to selection: Not only does traditional behavior, like all behavior, depend on cer= tain genes – think of the genes necessary for human speech, for example, or tool making—but traditions themselves, because they are inheritable, = are subject directly to selection. A tradition [is] distinguished as learned behavior copied from ancestors, like any trait begins for a variety of reasons.= But when it helps to leave descendants it will tend to increase in frequency. When it does not, = it will tend to die out.

Therefore, when we look at any widespread tradition that looks like it [has] been arou= nd for awhile, we can try to figure out how it helped individuals in the past = to leave descendants. That disco= very can explain why that tradition is widespread. Take religious behavior, for examp= le, which tends to be highly traditional; that is, individuals tend to acquire = the religion of their ancestors. Regardless of the truth of a religion, if it did not help individual= s to leave descendants, it would die out; it would disappear. So a crucial task in understanding= why a particular religion is widespread is to figure out how it helped the ancest= ors of the current followers to leave descendants. Of course, there is no guarantee t= hat any tradition will necessarily help individuals to leave descendants in the future.

While kinship behavior is exhibited by many species—all MAMMALS, for exampl= e, depend utterly on their mother’s care when young—humans in all societies, through traditions, have extended such behavior to many distant kinsmen and, within the last few thousand years, even to non-kinsmen. Based on the number of people exhi= biting such extended kinship behavior today, it must have been highly successful in the past; it must have dramatically increased the success of ancestors to l= eave descendants. In all societies, humans not only have a set of kinship terms—such as mother, son, neice and so on—used to identify their close relatives, these same terms are used metaphorically to identify distant kin, and today in modern societies, non-kin: “brother, can you lend me a dime?; “father”, the priest or Pope; “brother John, Sister Mary”; “George Washington, the “father” of our country; “Four score and 7 years ago, our forefathers brought forth . .= .” “Uncle Joe,” our parents’ friend.

But before we go further into these delightful examples, and try to account for this metaphorical usage, we must deal with what we mean by actual, true kin= ship and kinship behavior. What DISTINGUISHES the two?

Two individuals are kinsmen only when they are linked by birth; that is, one is= the ancestor of the other, or they share a common ancestor, they are co-descendants, such as siblings or cousins, or uncles and nieces. Thus, individuals are kin when the= y are an ancestor (including a parent) or a descendant (including one’s chi= ld), or as a co-descendant NO MATTER HOW DISTANT. Thus, if we assume we share a comm= on ancestor with chimpanzees, then we assume we are co-descendants, kinsmen of= one another—some kind of distant cousins. In fact, most evolutionists ass= ume that chimps are our closest cousins not in our species.

So, the definition of kinship is simple: individuals connected by birth. But what is meant by kinship BEHAV= IOR, for not all kinsmen act like kinsmen toward one another. Male lizards, for example, donR= 17;t care for, or identify their own offspring and may even pursue and eat them. Somehow, this is = not quite what we mean by kinship behavior.

Perhaps the best way to make explicit what we mean by kinship behavior is to look at motherly care, a behavior distinguishing mammals. No mammal would survive without it= . The term “mammal” comes from the Latin term for “breast”= ;, MAMMA, which is used by the females to give nourishment—milk—to their offspring. Germans focu= s on the other end of the operation, calling the mammalian category “Saeugling”, or “suckers”. This category of course incl= udes not just humans, but rats, giraffes, elephants and whales. The important point about motherly= care is that it is at the expense of both her survival, to some extent, and her future reproduction. She̵= 7;s giving nutrients that could help keep her alive and healthy, and when she is fully nursing she cannot reproduce. Keep in mind, surviving and reproducing are crucial traits necessary= for leaving descendants. But for mammalian females, they are not sufficient. In nature, if a female does not nurse her offspring, she will not leave descendants. All our mammalian ancestresses, ba= ck to the first mammal, nursed their offspring.&= nbsp; In tribal societies, like the one I lived in for 2 ½ years in= New Guinea, human mothers nurse their offspring for years. Thus, motherly care is distinguish= ed by sacrifice.

= Now, even though it is at the expense of the mother’s survival= and reproduction, because it is extremely widespread, nursing offspring must ha= ve significantly helped the mother to leave descendants, in contrast to alternative behaviors, such as with turtles, for example, which do not care= for their young, can live much longer, and can have far more offspring than fem= ale mammals. Yet motherly care, a= t the expense of the mother’s survival and reproduction, has been strongly selected for.

Motherly care, clearly, is kinship behavior; some might even say it epitomizes it. But here’s an important question. Is ANY behavior of = the mother directed toward her child kinship behavior? Although we have no word for it, l= ike patricide or matricide, perhaps because it’s so rare, what of the mother’s behavior who not long ago killed her three young children by putting them into her car and sending it into a lake, drowning them? She did this apparently in order t= o win a better mate? Surely, whatev= er we mean by kinship behavior, it is not just any behavior between kinsmen. Matricide, patricide or fratricide= , is not what we mean by kinship behavior, although it is between kin.

So what, then, do we mean by kinship behavior? First, it is behavior between kin,= but, apparently, not just any behavior. The Greek word for kinsmen, philoi, is almost identical to their word for love, philo. We translate= the name Philadelphia<= /st1:City>, for example, as the city of “brotherly love”. “Brotherly love is love like= that which often occurs between siblings. = Our words “gentle” and “gentleman” are based= on the Roman word for kinsmen or clansmen: “gens”—g-e-n-s. Jews used this word to refer to the “tribe” of Romans: gentiles.&n= bsp; So our word gentle and gentleman must mean something like behaving toward someone as if they were your kinsmen. What I’m suggesting is this: kinship behavior seems to imply some personal sacrifice aimed at benefiting another individual because he or she is your kinsman. Perhaps that sacrifice, too, like = that of a mother caring for her child, is at the cost of some survival and/or reproduction.

Now the important question: is sacrifice for any kinsman what we mean by kinship behavior? If that were so, any sacrifice toward any HUMAN would be kinship behavior, because we all share a common ancestor (who lived only about 100 thousand years ago). But clearly that is not what= we mean by true kinship behavior. What we must mean by kinship behavior, then, is that the sacrifice be correlated with the degree of kinship. T= hat is, only when the degree of sacrifice is correlated with kinship distance&#= 8212;defined as the number of birth links separating kinsmen—is it considered kins= hip behavior. Other sacrifice may= be seen as kinship-like behavior, or metaphorical kinship behavior. When you sacrifice for your mammal= ian puppy—feeding him, paying for a vet etc.—you act like his parent. And he responds to yo= u a bit like your child, accepting your “parental” influence and wanting to be with you constantly.

As mentioned above, humans in all societies traditionally use close kinship te= rms to encourage kinship behavior that is not correlated with genealogical distance. That is, humans everywhere encourage metaphorical kinship behavior. How did this come about? How did such traditions help leave descendants?

To do this, we must first address the question: how was TRUE kinship behavior selected for? That is, how di= d the degree of sacrifice, based on how close the kinsman is, help to leave more descendants than alternative behavior?&nbs= p; That answer seems pretty clear: close kinsmen share a lot of the same genes, with the closer kinsmen sharing more than distant kinsmen. A parent and offspring share half = of their genes, full siblings, on average, do also. First cousins share, by common des= cent, 1/8 of their genes. So when o= ne helps an offspring or full sibling, one is helping half of one’s genes. That is, when one help= s a close relative one is promoting the chances of one’s genes getting in= to the next generation. Thus, an= y gene promoting such behavior can increase through success in leaving descendants; that is, through Darwinian selection.

But in all human societies, ancestors promote close kinship behavior between distant or non kin, and such behavior cannot be explained by the sharing of genes.

Based on my reading and experiences in New Guinea and elsewhere, the= only explanation is traditions. Su= ch traditions, like all traits, depend on certain genes—in this case, ge= nes that are involved in large brains, speaking, copying and so on. The genes involved in the traditio= ns that promote kinship-like behavior are the same genes involved in true kins= hip behavior. But because humans = have been selected to copy their ancestors, and accept detailed instructions from them, ancestors have been able to encourage their descendants to refer to distant kin by close kin terms and to sacrifice for them as if they were cl= ose kin, to some extent. This app= ears to be true in all tribal societies, and therefore must have promoted greatly success in the leaving of descendants.&nbs= p; All members of the clans of each of one’s parents, for example, are typically called “brother” and “sister”, or, wh= en older, “mother” or “father.” For anthropologists, this has often proved initially confusing, for individuals may be called true brother or sister when standing in front of them, but only later does the anthropologi= st discover they are only distant kin. It is metaphor that is said openly to be true, but known to be not true. And tribal religion, wh= ich everywhere seems to include ancestor worship, promotes directly this kinship-like behavior. When descendants come together to worship their common ancestor, they often call each other “children” of that ancestor, making them metaphorical “siblings” of one another.&nbs= p; And they so refer to each other.

But kinship-like behavior is encouraged in all modern societies between non-kin, perhaps even more than between distant kin. How has this truly metaphorical be= havior come about? I think it is the result of the influence of prophets. Within the past several thousand years, prophets have arisen who, ba= sed on their supernatural claims—usually they claim to speak for the orig= inal ancestor, called father or mother – have gained followers who are encouraged to treat each other as if they were brother and sister, REGARDLE= SS OF THEIR TRUE KINSHIP RELATIONSHIPS. According to translators, Jesus, when told that his mother and breth= ren were waiting for him outside, said to his followers, “Who is my mother and my brethren? You are my m= other and my brethren when you follow me.”= He said also, “the only way to the Father . . . is by me.” Another statement: “Leave yo= ur mother and father, and follow me. Those who will not, are not worthy of me.” Prophets create a “family= 221; [made up of] individuals who are encouraged to sacrifice for one another as= if they were brothers and sisters. The fundamental significance of all successful prophets may be that,= by creating a religion, they create a set of individuals who are encouraged to sacrifice for one as if they were close kin. I’m suggesting here, that the effect of all religion that has helped individuals to leave descendants may= be that they are encouraged to treat one another as if they were close kin (to some extent).

What is the benefit of this kinship-like behavior between distant or non- kin? First, it reduces competition, inc= luding violent competition, among them. They are safer. Second= ly, it promotes cooperation among them. And this cooperation regularly includes trade and some specializatio= n, which is the basis of a higher standard of living. For prophet-created religions̵= 2;modern religions—this has led regularly to extensive trade and specialization. This trade and specialization, which today includes the discoveries of science, medicine a= nd technology, not only benefit the individuals involved, but also their child= ren and further descendants. Today, education is an important part of this strategy, for educatio= n is aimed at teaching children the skills and knowledge crucial to these specializations. And parents everywhere are the main supporters of education for their children; they are the ones who always vote yes on school bills. Sun City always defeats them. Modern education is still a kinship strategy aimed at leaving descendants.

In most religious hierarchies, close kinship terms are used. Buddhist monks often call each oth= er “brother”, sometimes specified further by “older” or “younger”. Cathol= ic monks speak of each other in the same way.= Fraternities—“brotherhoods”—are widespread.<= span style=3D'mso-spacerun:yes'> A term often used in the Arab worl= d for informal leaders is “Abu” (“uncle”, I believe), suc= h as the current Palestinian leader. There is Abu Nidal, an old terrorist, and also Abu Musab al Zarqawi,= of current Iraqi fame. We, on the other hand, not only have a “father” of our country, but Uncle = Sam.

<= span style=3D'font-size:12.0pt'>The metaphorical use of kinship terms, and the encouragement of kinship-like behavior, is ubiquitous among humans, indicat= ing its fundamental importance. Traditions, including, or perhaps especially, religious traditions h= ave been involved in this extension of kinship behavior. But these are only the mechanisms.= The fundamental explanation of why= they are widespread is based on the discovery, 150 years ago, of selection. If those traditions had not promot= ed success in leaving descendants of those exhibiting them, they would never h= ave become widespread.

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One last, brief point: one that may be of particular interest to architectural professors. Monumental architecture, including pyramids, ziggurats, temples, cathedrals, and perha= ps even modern soaring, breath-taking buildings and statues— seen for example all over Washington D.C.—have not been well-explained. Writers have offered a number of suggestions but none seems to fit the evidence. None explains the great expense necessary to their creation. I believe such monuments are monuments to sacrifice. Their aim: to promote sacrifice am= ong the observers. When we come a= cross a monument we are struck by the fact that it is made by humans, but also by= the fact that there is no practical or obvious explanation for it. (Despite being bombarded today by = the speculations of scientific sleuths). Clearly, monuments represent great sacrifice of those who had them built, and. interestingly, it is usually sacrifice for ancestors. A creator God represents the first ancestor. And a prophet, to h= is followers, is accepted like an ancestor, for he is the creator of their traditions. Here, in the [V]a= lley [of the Sun, or Phoenix, Arizona], the large platform mounds bu= ilt by the ancient Hohokam are also like to have represented sacrifice to their ancestors, as well as the Casa Grande to our South. The significant effect of ancestor worship is that it promotes respect for ancestors and what is important to them: their descendants, co-descendants of one another, and their tradition= s. Thus, ancestor worship, as a ritua= l of co-descendants, promotes the basis of all human societies: kinship cooperat= ion and traditions. And monuments= seem to have a lot to do with this.

Thus, to sum up this point: the architectural profession may be nobler than some have realized.<= /span>