Altruism (zoology)

Those who study behavior have observed that, on occasion, individuals act altruistically. In other words, they appear voluntarily to put the needs of their group or of another individual ahead of their own needs. According to some scientists, there have been examples in nature where a particular species might not have survived had there not been sacrifice by some on behalf of the many. One important question is whether this so-called altruism has been a matter of voluntary choice or whether it has occurred as a part of the selection process, making it, therefore, an involuntary response.

Group Dynamics

Of interest to a wide group, including psychologists, sociologists, philosophers, and political scientists, are the questions of whether altruism is desirable behavior—perhaps even to the exclusion of egoism—and whether altruism may be necessary for human survival. Some wonder whether such behavior is necessary, whether it can be learned, and whether humans will voluntarily choose to learn it. Biologists and geneticists aim to determine, if possible, whether the tendency for altruism is an inherited, instinctual trait or a learned behavior. Studying human beings in social groups in the wild is virtually impossible. However, the study of animal behavior, primarily in native habitats, has provided some insight, although it must be recognized that different species have solved problems of survival in different ways.

Animals of the same species are bound to consort, if only for mating purposes. Many species live in groups, not only for purposes of reproduction but because sources of food attract individuals to the same places and because congregation provides better protection from predators. It is common in nature for groups to form because their individuals have the same physical needs, and such groups may stay together as long as the needs of those individuals can be met. This does not necessarily mean that there exists in the group any loyalty or even any recognition of individuals as members of the group. In more highly developed societies, however, groups, such as families or tribes, develop. In animal life, two or more adults and their offspring often form close bonds and tend to exclude those who are not related. Each recognizes the others as being members, and membership is restricted to those who are among the founders or who are born into the smaller group and who conform in recognizable ways to the norms of the group. Hierarchy or rank is recognized, and often, there is a division of labor within the group.

Research indicates that species that spend significant time providing for their young tend to have developed higher social orders. Humans, for example, must care for their young for much longer before they reach independence compared to many lower forms of animal life. Humans are aware of a bond that almost always exists between parent and child and of the spirit of mutual support and cooperation that may exist even in the extended family. Cooperative behavior within such a familial group may be considered to benefit all members. Because such behavior is not consistent, there are times when such bonds do not exist and when families are not cooperative. Such behavior cannot necessarily be attributed to predisposition. Some have argued that in primitive animal societies, so-called altruism may have evolved out of necessity to achieve reproductive success. However, in human society, there may be no evolutionary explanation for the phenomenon. Indeed, it could be argued that pure altruism, for humans, might be self-defeating and, therefore, unlikely to have developed as an inherited trait.

Scientists have documented many examples of altruism in nature among mammals, birds, fish, and sea creatures. For example, a group of sperm whales in Portugal adopted a young bottlenose dolphin with a spine abnormality who was abandoned by its pod. The sperm whales were observed reciprocating the dolphin’s affectionate side rubs, and the sperm whale claves played and foraged with the dolphin. Another example of group animal altruism is observable in vampire bats. These bats regurgitate and share blood with those in their group who could not feed that day.

Kin Selection and Reciprocal Sacrifice

Scientists have identified evidence of altruism in studying insects in the order Hymenoptera, which includes sawflies, wasps, bees, and ants. These insects provide food for their young, and certain members of the population forage for the group while others lay eggs and remain at the nest to guard them. Where such behavior has evolved, through the necessity of feeding and protecting those who will propagate their kind, the foragers may be labeled altruistic—they have sacrificed their own reproductive possibilities for the group's survival. Some have questioned whether this phenomenon can truly be labeled altruism because the donor appears to have no choice (conscious purpose is very difficult to assess in animals). Moreover, some researchers wonder how the traits that favor altruistic behavior can survive and become dominant in a group if those having the traits deemed desirable are not allowed to reproduce. With the use of mathematical models, it has been demonstrated that such traits can be preserved only within the family unit. Among close relatives, the traits appear with enough strength that they will be reproduced in a greater concentration, thereby compensating for the loss suffered by the sacrifice of the donors. This phenomenon has been referred to as kin selection because it occurs in groups that have strong recognition of membership—to the extent that there exists aggressive defense against intruders, even of the same species. Discrimination against outsiders is an important facet of altruism of this type. The willingness of an individual to provide for others at the expense of their own interests diminishes as the degree of relatedness decreases.

Most parental behavior would not be labeled altruistic since it is in the interests of the parent to care for the offspring to ensure the survival of the parent’s genes. Of perhaps more interest is the question of what motivates sacrifice on the part of an individual when no close relationship with the recipient exists—for example, a male animal coming to the rescue of an unrelated male animal who is being attacked by a third male of the same species. One theory maintains that these acts of personal sacrifice are performed on the chance that reciprocal sacrifice may occur at some future time. Whether this type of altruism can occur through natural selection, which acts through individuals, is an interesting question. Models have shown that in a population where individuals are likely to encounter and recognize one another on a frequent basis, it is possible that reciprocal exchanges can take place. Individual A might be the donor on the first encounter, but individual B on the second. This theory requires that the two must have a high probability of subsequent encounters and that the tendency for altruism must already have been established through kin selection. Because animals are usually suspicious of strangers on first encounter, it is necessary to speculate that, in its beginning, altruism was a selected-for trait in very small groups where strangers were not only non-hostile but also likely to be relatives and likely to be met again. This type of behavior, in which individuals act in a manner not to their own advantage and not in an order that their own genes or the genes of relatives will survive, is done, in theory, with some expectation of imagined reciprocal gain. How this type of behavior has come about, however, is a matter requiring further study.

Another question concerns how much culture influences the development of a hereditary tendency toward altruism. Some have suggested that after generations and generations of cultural emphasis on the need for altruism, it might come to have a genetic basis. There is little hard evidence that this would occur. On the other hand, humans have had a very rapid cultural evolution, and it is possible that they may have had strong genetic propensities for altruism, which have been culturally overlaid. Some argue that biology and culture evolve simultaneously—that the culture is formed as a result of the imposition of genetic factors while, at the same time, genetic traits are evolving in response to cultural change. To understand the source of altruism in humankind, one must study such behavior in the context of many factors in human development—biological as well as social, cultural, economic, and ecologic.

Studying Altruistic Behavior

Those investigating the sources of altruism usually begin with a thorough understanding of whatever organism is the subject of the study. When the insect or animal cannot be studied in the wild, the ethologist tries to simulate the important features of the natural habitat in a captive environment, at least in the beginning. Models are devised, based on observable data; formulas are employed; and projections are made which provide a basis for speculative argument when absolutes cannot be assured.

By observing, it is possible to determine whether various bits of evidence of altruism exist within a population. Altruism may be manifested in as simple a way as the sharing of food when there is a scarcity. In some populations, one might observe a division of labor in which some forfeit their reproductive possibilities to care for the offspring of others. This phenomenon introduces the question of how altruism can survive in a population in which the genetic traits favoring the behavior are most evident in the individuals who do not reproduce themselves. It has been shown that the tendency for altruism can be perpetuated only within the family unit, where the same genetic tendency exists to some degree in members that engage in reproductive activity; this can be demonstrated by a mathematical formula.

Each individual bears the inheritance coefficient, or relatedness coefficient, r. Offspring share with each parent an average of half of the genetic traits of each (r = ½). Offspring share with each grandparent one-fourth of the genetic traits of each of the older generations (r = ¼); the same coefficient exists with cousins. Were the altruists not to reproduce, it would be required, for the trait to be passed on, that the reproductive chances of their siblings more than double or that the reproductive chances of their cousins more than quadruple. For the sacrifice to be of value, the genetic relationship must be close, according to the demonstration. The case has been made that in societies having evolved according to this principle, there is a diminishing willingness to put the interests of others ahead of one’s own as the degree of kinship decreases.

In societies where males are produced from unfertilized eggs and females from fertilized ones, female offspring of a mated pair have a high relatedness coefficient (r = ¾). The altruists among the female siblings will benefit more, regarding their genetic potential, by caring for their sisters than for their own offspring, and it can again be observed that sacrifice is more likely to be made on behalf of the member that is more closely related.

The Value of Altruism

If altruism exists in nature, and if it has come about through natural selection, then one can argue that it must be a behavior with value. When applying the human connotation to the term altruism, however, one must consider the role of choice in the manifestation of the behavior. Humans claim to admire acts of unselfishness that are seemingly done with no expectation of reward. The admiration would diminish or become nonexistent, however, if there were to be proof that the act was performed because of some primitive biological predisposition rather than because of a decision on the part of the donor. Therefore, it is necessary to make the distinction, when discussing the importance of altruism, as to whether one is referring to the acts of human beings that are performed in the face of emergency or tragedy, where a sacrifice is made as a matter of choice, or whether the intent is to consider altruism as it occurs in other creatures and seems to be involuntary.

In the case of nonhuman forms, altruism as an act of voluntary sacrifice is infrequent—if indeed it exists at all. Altruism, however, as an act that is dictated by genetics, is observable, and it has been shown to have been necessary for the survival of certain species. Where animal societies have formed in which some members of the society have spent their lives caring for the offspring of others or performing other sacrificial behavior that benefits the group, there can be little doubt that such altruism has been dictated by nature for its own unique purposes. Moreover, the fact that voluntary self-sacrifice on the part of human beings exists does not automatically make it desirable human behavior any more than aggressive, even warlike behavior is automatically undesirable. The case can be made that both types of behavior are important. Perhaps the larger question is when and under what circumstances certain types of human behavior should be acceptable or desirable for the individual and for the group, and, even more important, who is qualified to decide what type of behavior is appropriate.

Principal Terms

Altruism: Sacrifice of self to aid another; subjugation of the needs of the individual to the needs of another or to the needs of the group

Egoism: Self-interest

Hymenoptera: An order of highly specialized insects (including bees, ants, flies, and wasps) that often associate in large colonies and have a complex social organization

Kin Selection: A phenomenon by which acts of altruism can help pass on genes for altruism by improving the survival of kin and their offspring

Reciprocal Sacrifice: One explanation for acts of altruism among unrelated animals; an individual sacrifice is made under the assumption that a similar sacrifice may, in turn, aid the individual in the future

Selection: A process that prevents some individuals from surviving and propagating while allowing others to do so

Trait: A genetically inherited characteristic

Bibliography

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