Altruistic Behavior
Behaviors that lower the fitness of the individual but increase the fitness of another individual are termed altruistic. Examples of such behaviors are seen widely across the animal kingdom. Social insects such as worker bees have no ability to reproduce, yet they maintain the queen so she can populate the hive with her offspring. Meerkats keep a member of the group standing guard to warn the rest of the colony about
intruders, even though the guarding meerkat is putting itself at risk. Wolves and wild dogs bring meat to pack members not present during a hunt. Although on the surface, these behaviors appear to be altruistic, it may not be so simple.
There has been much discussion over why altruistic behaviors exist. Do these behaviors lead to overall evolutionary advantages for their species? Do they help the altruistic individual pass on its own genes? One explanation for altruistic-type behaviors is found in the genetics of natural selection. In the 1976 book, The Selfish Gene, scientist Richard Dawkins attempted to explain many seemingly altruistic behaviors from the viewpoint of the gene itself. Although a gene obviously cannot be selfish in the human sense, it may appear that way if the sacrifice of an individual benefits related individuals that share genes that are identical by descent (present in relatives because of common ancestors). Mammal parents make this sacrifice to take care of their offspring. Emperor penguins migrate miles in harsh conditions to bring food
back for their young. Selfish gene theory has been controversial over the years and is still discussed among scientists in related fields.
Even less-related individuals with less genetic identity than those shared by parent and offspring benefit from seemingly altruistic behavior. The activities of social insects such as bees, wasps, ants, and termites are good examples. Sterile workers in these societies take care of the queen because they are closely related to it, and as the queen has offspring, she is passing on genes from the workers indirectly. Thus, it is
of fitness benefit for the worker to maintain the queen without having any direct chance of passing on its genes due to its sterility. This phenomenon can explain many superficially altruistic behaviors seen in animals. However, these behaviors may not be truly defined as altruism in these cases because the actor is actually increasing its own fitness either directly (through its own offspring) or indirectly (through the inclusive fitness it gains through relatives that share genes with it).
Unrelated individuals may also act altruistically to each other, and this seems to defy the “selfish gene”explanation. An example of this has been observed in many monkey species where a monkey will present its back to an unrelated monkey to have that individual pick the parasites from its fur. After a certain amount of time, the roles are reversed and the first monkey now grooms the second monkey. Thus, there
is reciprocity in the behavior. Both benefit from the interaction and their fitness is raised more than if neither cooperated nor if one cooperated and the other did not cooperate. This behavior is still not necessarily altruistic, as the “giving” behavior of the actor is based on the expectation that it will be the “receiver” of the behavior in the future, termed reciprocal altruism. Reciprocal altruism requires that individuals repeatedly encounter each other, often the result of living in the same social group and that cheaters (those that never “give back”) are punished.
Evolutionary game theory, a modification of classical game theory in mathematics, has shown that many of these so-called “altruistic behaviors” are not altruistic at all. The definition of “pure” altruism, based on human behavior, is an action that benefits another without any direct benefit to oneself. Most of the behaviors previously described do not seem to satisfy this definition, and game theorists are good at
finding “selfish” components in them. Others have argued that the terms “selfish” and “altruistic” should be dropped completely when discussing animal behavior, as they describe human behavior and may not be directly applicable to instinctual animal activity. What is clear, though, is that heritable behaviors that improve the chances of passing on one’s genes or a portion of one’s genes are favored by natural
selection and will be retained in future generations as long as those behaviors convey a fitness advantage.
Source: OpenStax (2019). Behavioral biology: Proximate and ultimate causes of behavior.
Reading Paragraph 1
Behaviors that lower the fitness of the individual but increase the fitness of another individual are termed altruistic. Examples of such behaviors are seen widely across the animal kingdom. Social insects such as worker bees have no ability to reproduce, yet they maintain the queen so she can populate the hive with her offspring. Meerkats keep a member of the group standing guard to warn the rest of the colony about
intruders, even though the guarding meerkat is putting itself at risk. Wolves and wild dogs bring meat to pack members not present during a hunt. Although on the surface, these behaviors appear to be altruistic, it may not be so simple.
1. According to paragraph 1, which of the following is true?
a. Altruistic actions in nature decrease one’s ability to survive while improving the fitness of others
b. Worker bees are social insects that guard the colony and produce offspring with their queen
c. Meerkats work in groups to defend and warn their community against intruders
d. Wild dogs bringing meat back from a hunt is a well-understood altruistic behavior
Reading Paragraph 2
There has been much discussion over why altruistic behaviors exist. Do these behaviors lead to overall evolutionary advantages for their species? Do they help the altruistic individual pass on its own genes? One explanation for altruistic-type behaviors is found in the genetics of natural selection. In the 1976 book, The Selfish Gene, scientist Richard Dawkins attempted to explain many seemingly altruistic behaviors from the viewpoint of the gene itself. Although a gene obviously cannot be selfish in the human sense, it may appear that way if the sacrifice of an individual benefits related individuals that share genes that are identical by descent (present in relatives because of common ancestors). Mammal parents make this sacrifice to take care of their offspring. Emperor penguins migrate miles in harsh conditions to bring food
back for their young. Selfish gene theory has been controversial over the years and is still discussed among scientists in related fields.
2. The book The Selfish Gene deals with
a. The debate about why organisms behave altruistically
b. The popular theories scientists have on altruistic behaviors
c. The author’s explanation of altruistic behaviors
d. Altruistic behaviors in humans with genes of identical descent
3. Why does the author say, “Emperor penguins migrate miles in harsh conditions to bring food back for their young”?
a. To explain why emperor penguins travel so far for food
b. To show that emperor penguins are birds that sacrifice the most for their young
c. To provide an example of altruistic behavior
d. To highlight how some altruistic behaviors fit the model of selfish gene theory
Reading Paragraph 3
Even less-related individuals with less genetic identity than those shared by parent and offspring benefit from seemingly altruistic behavior. The activities of social insects such as bees, wasps, ants, and termites are good examples. Sterile workers in these societies take care of the queen because they are closely related to it, and as the queen has offspring, she is passing on genes from the workers indirectly. Thus, it is
of fitness benefit for the worker to maintain the queen without having any direct chance of passing on its genes due to its sterility. This phenomenon can explain many superficially altruistic behaviors seen in animals. However, these behaviors may not be truly defined as altruism in these cases because the actor is actually increasing its own fitness either directly (through its own offspring) or indirectly (through the inclusive fitness it gains through relatives that share genes with it).
4. The word superficially in paragraph 3 is closest in meaning to
a. Apparent
b. Artificially
c. Creatively
d. Beneficial
Reading Paragraph 4
Unrelated individuals may also act altruistically to each other, and this seems to defy the “selfish gene”explanation. An example of this has been observed in many monkey species where a monkey will present its back to an unrelated monkey to have that individual pick the parasites from its fur. After a certain amount of time, the roles are reversed and the first monkey now grooms the second monkey. Thus, there
is reciprocity in the behavior. Both benefit from the interaction and their fitness is raised more than if neither cooperated nor if one cooperated and the other did not cooperate. This behavior is still not necessarily altruistic, as the “giving” behavior of the actor is based on the expectation that it will be the “receiver” of the behavior in the future, termed reciprocal altruism. Reciprocal altruism requires that individuals repeatedly encounter each other, often the result of living in the same social group and that cheaters (those that never “give back”) are punished.
5. All of the following are true EXCEPT
a. Some species of monkeys behave altruistically to others they are not related to
b. When monkeys practice reciprocal altruism both participants gain
c. Reciprocal altruism cannot really be considered altruism
d. Reciprocal altruism occurs mostly in monkeys of the same species
Reading Paragraph 5
Evolutionary game theory, a modification of classical game theory in mathematics, has shown that many of these so-called “altruistic behaviors” are not altruistic at all. The definition of “pure” altruism, based on human behavior, is an action that benefits another without any direct benefit to oneself. Most of the behaviors previously described do not seem to satisfy this definition, and game theorists are good at
finding “selfish” components in them. Others have argued that the terms “selfish” and “altruistic” should be dropped completely when discussing animal behavior, as they describe human behavior and may not be directly applicable to instinctual animal activity. What is clear, though, is that heritable behaviors that improve the chances of passing on one’s genes or a portion of one’s genes are favored by natural
selection and will be retained in future generations as long as those behaviors convey a fitness advantage.
6. What have game theorists discovered about altruistic behavior in animals?
a. Most do not qualify as truly altruistic because they involve selfish aspects
b. The majority of animals engage in altruistic behavior
c. Evolutionary game theory contradicts classic game theory in math
d. The true definition of altruism is an action that does not benefit oneself in any way
7. What can be inferred from the information in paragraph five?
a. Most animals are selfish beings by nature
b. There is more than one definition of altruism in the animal kingdom
c. People argue about selfish and altruistic behaviors in animals frequently
d. It is instinctual for animals to behave in ways that preserve their genes
8. Which of the following best expresses the essential information in the highlighted sentence in paragraph 5? Incorrect choices change the meaning in important ways or leave out essential information.
a. Animals will always continue to engage in behaviors that preserve their genetics
b. Actions that preserve one’s genes and remain advantageous to its fitness will continue in future generations
c. Natural selection is marked by animals who act in ways that increase the chance of passing on their genes
d. Behaviors that are advantageous to one generation will be passed on to the next
9. Look at the four squares (A, B, C, D) that indicate where the following sentence could be added to the passage.
Altruistic behaviors are not exclusively witnessed in humans.
Where would the sentence best fit?
A Behaviors that lower the fitness of the individual but increase the fitness of another individual are termed altruistic. B Examples of such behaviors are seen widely across the animal kingdom. C Social insects such as worker bees have no ability to reproduce, yet they maintain the queen so she can populate the hive with her offspring. D Meerkats keep a member of the group standing guard to warn the rest of the colony about intruders, even though the guarding meerkat is putting itself at risk.
10. DIRECTIONS: An introductory sentence for a brief summary of the passage is provided below.
Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
Some animals behave in ways that seem altruistic, and while there are several explanations for this, there is also an argument that animal behavior is not and cannot be deemed altruistic.
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a. There are a variety of examples of altruistic behavior in the animal kingdom
b. Richard Dawkins was a genetics scientist who wrote a book in 1976 called The Selfish Gene
c. A strong explanation for altruistic behaviors is the instinctual desire to pass on one’s genes
d. All species of monkeys engage in what is called reciprocal altruism
e. Some argue that it is best not to apply the terms that describe human behavior to animal behavior
f. Emperor penguins travel great distances just to get food for their offspring
Passage #1 - Altruistic Behavior
1. A
2. C
3. D
4. A
5. D
6. A
7. D
8. B
9. B
10. A, C, E
Altruistic Behavior: Answer Key
Source: OpenStax (2019). Behavioral biology: Proximate and ultimate causes of behavior.
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