The Connection Between Culture & Natural Selection Through the Example Of Chimpanzees
Chimpanzees are highly social creatures which are exclusive to Africa. These creatures live in multi male and multi female groups with a social hierarchy. As a species, Chimpanzees readily exhibit a repertoire of cultural behaviors. These behaviors, much like the behavior in humans, is the result of natural selection and evolution.
Some of the many social elements that define Chimpanzee culture include:
· Social hierarchy (males and females)
· Social acceptance of leadership positions
· Altruistic behavior
· Nonverbal communication
These elements are often not considered in terms of culture due to the lack of cultural artifacts. However, cultural artifacts are present and help to show the connection between natural selection and culture in this species.
In order to understand the connection between Chimpanzee culture and natural selection, one must understand evolution and the mechanism of natural selection. Evolution is a multigenerational and multiindividual process. In its simplest definition, evolution is the process of change in heritable traits of species over successive generations (Hall & Hallgrímsson, 2008). The evolutionary process exists in this manner because pressures from the environment must happen over time in order to impact change in a species (Chiras, 2013). For example, if chimpanzees that eat vegetables and meat existed alongside of chimpanzees that eat only vegetables, then the chimpanzees who eat exclusively vegetables would be impacted by reductions in food supply. If over generations, there was less vegetables to eat, fewer and fewer vegetable eating chimpanzees would survive. If this trend persisted over time, the individual chimpanzees who could only feed on vegetables would slowly die out leaving the meat and vegetable eating chimpanzees. This evolutionary process is specifically known as natural selection. The more advantageous traits of a species allow those creatures who possess them to survive breed and increase their populations. Those creatures without advantageous traits die out.
Because evolution is complex, there are many advantageous traits which species may possess. Culture and socialization is considered to be an advantageous trait because it allows for creatures to better survive by sharing common work and practices. The unity which culture creates provides a means of protecting the species and likely leads to more unified groups which can withstand predators and other elements which may threaten the group.
Natural Selection and Culture
In the context of culture, Darwin sees no difference between humans and any other species. Darwin believes that culture and social practices evolved by selection through group differences:
It must not be forgotten that although a high standard of morality gives but a slight or no advantage to each individual man and his children over other men of the same tribe, yet that an increase in the number of well-endowed men and an advancement in the standard of morality will certainly give an immense advantage to one tribe over another. A tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to aid one another, and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection (Darwin, 1859).
Within this framework, Darwin viewed culture and natural selection in a somewhat paradoxical manner. While culture may form from natural selection, by dominant groups utilizing best practices in order to further their lineage, natural selection is also weakened by culture. Darwin discusses this weakening of natural selection in terms of morality:
…on the causes which lead to the advance of morality, namely the approbations of our fellow men-the strengthening of our sympathies by habit — example and imitation — reason — experience, and even self-interest — instruction during youth, and religious feelings‖ (Darwin, 1859).
As humans adopt cultural practices they inadvertently weaken the natural selection process in a trade for the benefits of that the culture affords them. For example, the richest and most technologically advanced countries in the world — have the lowest population growth rates (below 1 percent) (Macionis, 2011).. The poorest and least technologically advanced nations have the highest population growth rates (2.4 percent) (Macionis, 2011). Because these countries have the least amount of resources and infrastructure, the growth rates in poor less advanced cultures are unsustainable. One of the most important cultural factors that impacts population growth is education in women. In nearly all societies, women with more education tend to marry later and have fewer children (Berg, Hager, & Hassenzahl, 2011). Providing women with educational opportunities delays their first childbirth, thereby reducing the number of childbearing years and increasing the amount of time between generations. While this is beneficial to cultural growth it cuts against the grain of natural selection by inhibiting mating practices.
The mechanism of natural selection is present in all life forms and the link between culture and evolution can be seen in species such as Chimpanzee’s. When one examines Chimpanzee behavior, the effects of culture are readily seen.
Less than humans, Chimpanzees are the second most documented form of culture. Much of this study of Chimpanzee culture has only been recently documented. In review of the literature from the past 151 years, researchers determined that chimpanzees exhibit “39 different behavior patterns, including tool usage, grooming and courtship behaviors, are customary or habitual in some communities but are absent in others where ecological explanations have been discounted” (Whiten, et al., 1999). Because these patterns of behavior are not present in all communities of chimpanzees, they cannot be attributed to instinctual behavior (Whiten, et al., 1999).
Perhaps the most pronounced form of chimpanzee culture is found in the social hierarchy traditions which are learned within the communities. Chimpanzees have a hierarchal social structure with males controlling family units. Within these family units, there are descending orders of hierarchy both in males and females. These hierarchal relationships are learned through both physical violence but also through behaviors. For instance, the cracking of nuts by learning to use a stone as a tool, can be taught or learned through mimicking (Whiten, et al., 1999). This learning is a process which is different among the communities of chimpanzees. Some groups utilize stones for cracking nuts while other use wood (Whiten, et al., 1999).
The relationships between chimpanzees within family units is not dissimilar from human family relationships. For example, female chimpanzees show relationships between one another which are based on dominance but also on abilities. For example, females who are submissive but able to gather foods with skill are often found in closer relationships with dominant females (Whiten, et al., 1999).
Social Hierarchy among chimpanzee communities and families is likely the result of natural selection. Chimpanzees that understood how to use tools were more likely to survive than those who could not. Much like humans, chimpanzees were intelligent enough to teach their offspring how to use tools, thus furthering the line. But similar to humans, social hierarchy limits or weakens natural selection by creating practices such as limiting diversity. Weaker chimpanzees who understand and are skilled at tool usage are allowed to thrive within communities which limits their ability to be impacted by environmental forces.
Authority is a cultural element which is linked with socialization. Chimpanzee culture has definitive hierarchal structure with dominant or alpha males at the top then descending orders of authority throughout the group (Whiten, et al., 1999). Authority must on some level be understood or there would be no mean of unifying the family. The best way to understand authority in the cultural context of chimpanzees is from the different ways it manifests itself in family units.
While all Chimpanzee cultures maintain heirarcal family structures, authority within these structures is different in accordance with the family unit in question. For instance, some males, or alphas, are extremely violent towards subordinate males while in other family units there is less violent behavior (Whiten, et al., 1999). While this behavior may appear to be a temperament issue among males it is actually more cultural in nature. Violent male families tend to remain violent generation after generation (Whiten, et al., 1999).
Another manner in which authority can be understood as cultural in chimpanzees can be found in the way that authority is viewed in different ways. For example, in some family units, the females have been known to oust an alpha male. The reasoning for this may be from the potential benefit of the new male (Whiten, et al., 1999). This does not occur in all chimpanzee family units and appears to be a learned behavior (Whiten, et al., 1999).
From a Darwinian perspective, this behavior may have been learned through a natural selection process by which, female chimpanzees learned to recognize deficiencies in the mates and looked to find stronger mates to correct this problem. This perspective shows how the natural selection process is also weakened because, by learning to oust the alpha male, this reduces the probability of the more superior male asserting himself in a group (Whiten, et al., 1999). This explains why some Chimpanzee groups exhibit this behavior while others do not since it is a cultural manifestation.
One of the more unique cultural manifestations in chimpanzees, is their ability to be altruistic. Not only are chimpanzees observed to be altruistic to their family members but they have the ability to be altruistic when it comes to other species. Observations of chimpanzees in the wild have shown numerous examples of altruism such as feeding one another, helping one another such as carrying objects, as well as helping humans:
Current research thus suggests the possibility that chimpanzees are able and willing to help, but they display this behavior only in very restricted contexts. First, chimpanzees might help only a familiar human caregiver with whom they maintained a close relationship, based on a rearing history in which compliant behavior in other contexts had been reinforced. Second, chimpanzees might help others only if costs are low, whereas humans display much more costly helping (Warneken , Hare, Melis, Hanus, & Tomasello, 2007).
Altruism has long been considered an anomaly among primates with stories of apes saving humans. While altruism is limited in chimpanzees, mostly to family units, it does exist and it is a cultural manifestation. In chimpanzee families which exhibit altruism, this trait is performed often and in different ways depending on the family unit (Warneken , Hare, Melis, Hanus, & Tomasello, 2007). Clearly this is an element of evolution specific to what Darwin believes is a benefit that allows a species to thrive in a social sense but at the cost of natural selection:
…complexity and clumsiness of a coevolutionary system in which genes and culture are often collaborators but sometimes antagonists. Human ultra-sociality is a super adaptation that underpins our ecological dominance of Earth, yet it is much less perfect than the ultra-sociality of the ants, bees, and termites.
An interesting feature of Chimpanzee culture is that they exhibit nonverbal communications skills which serve the same purpose but also identify the individual using the skill. There are 30 different calls which chimpanzees use to identify or alert one another. These calls may alert other to food or to success in hunting (Whiten, et al., 1999). Most importantly, these communication’s skills also identify the individual using the particular call. This is a cultural phenomenon because only the chimpanzees who are part of the individuals family will recognize the call despite the fact that other family units are in the area.
Courtesy of Jane Goodall Institute
Language is a unique cultural manifestation because it differs within species. Verbal communication while similar between chimpanzee cultures, it is differentiated by family (Whiten, et al., 1999), gesticulations, sounds, and other factors specific to a chimpanzee community. Natural selection has allowed chimps that are able to communicate in this manner to differentiate themselves and to survive by being able to warn one another and to alert each other to food (Whiten, et al., 1999). This evolutionary factor may have also allowed chimpanzee families to survive due to understanding when other chimpanzees were in the area which could pose a threat to the family unit.
In the context of evolution, chimpanzee culture has evolved similar to human culture. There are several concepts which can be drawn concerning culture and natural selection. The first concept is that culture is intrinsically linked with natural selection. Creatures which possess culture are better able to navigate and survive their environments by creating and maintaining practices which enhance their survivability.
Chimpanzees, because of their social nature are able to group together to fend themselves from predators as well as to increase their ability to hunt and forage for food. Their culture has allowed them to create family units and communities which maintain practices and traditions that are unique to their collectives. From an evolutionary point of view, it appears that culture, at least in primates, is a necessary function or occurrence. This would mean that culture may be a necessary component of certain species which helps to ensure survival. This idea brings into question whether other species that are social in nature maintain cultural elements? More research is needed in this area.
Culture also appears to manifest itself in creatures such as primates which tend to have higher intelligence. There is a considerable debate as to whether intelligence dictates culture or vice versa. What appears to be intelligent in one culture may not be considered intelligent in another culture. This debate may be pointless as chimpanzee’s are of obvious and diminished intelligence but still maintain culture. This is aspect of intelligence shows that culture and intellect may also be intrinsically connected as only higher thinking species seem to maintain culture.
From a standpoint of natural selection, intelligence and culture may be the byproduct of lack of physical adaptability. While some creatures such as lions are sensitive to environmental changes and die quickly when factors such as their food supplies are altered; primates show a remarkable ability to adapt through the use of intellect and reinforcing best social practices with culture. In this sense, a human is one of the physically weakest creatures but yet is able to adapt to almost any environment through its use of intelligence and culture.
In contrast, species such as lions, while physically strong and able to withstand tremendous physical stress, are also the most vulnerable of species. This is due to the fact that they are dependent on environmental factors such as food supplies and water. Lions also have very little culture and operate more instinctively than collectively.
When one considers these concepts with regard to chimpanzees, it can be observed that while chimps are much stronger than humans, they are less intelligent. Their culture is much less complex than human culture. Within this context it may be assumed that because chimps are more physically resilient, they may also require less culture to help them survive.
The difficulty in these contemplations is that evolution and natural selection are much more complex then given credit. It is easy to draw connections between evolution and culture but these connections are not causal in nature. It is possible that culture is nothing more than a byproduct of intelligent species. Certainly, ants are collective social groups of creatures and one of the hardiest creatures in terms of survival. Yet, one would not consider ants in a cultural context. The connections between culture and evolution still have large areas of unknown and must be researched more in depth before drawing conclusions about them.
Berg, L. R., Hager, M. C., & Hassenzahl, D. M. (2011). Visualizing environmental science (3 ed.). Hoboken, NJ: Wiley.
Chiras, D. D. (2013). Environmental science (9th ed.). . Burlington, MA: Jones & Bartlett.
Darwin, C. (1859). On The Origin of Species: Including Darwins Notes. New York, NY: Signet Classics.
Hall, B. K., & Hallgrímsson, B. (2008). Strickberger’s Evolution (4 ed.). Sudbury, MA: Jones and Bartlett Publishers.
Macionis, J. (2011). Society: The Basics, Eleventh Edition. Prentice Hall, NJ: Pearson Education, Inc.
Simon, E. J., Reece, J. B., & Dickey, J. L. (2010). Essential biology with physiology. (3rd ed.). San Francisco, CA: Pearson/Benjamin Cummings.
Warneken , F., Hare, B., Melis, A. P., Hanus, D., & Tomasello, M. (2007). Altruism by Chimpanzees and Young Children. PLoS Biol , 5(7), 184.
Whiten, A., Goodall, J., McGrew, W. C., Nishida, T., Reynolds, V., Sugiyama, Y., . . . Boesch, C. (1999, June 17). Cultures in Chimpanzees. Nature, 399, 682–685.