Please enable JavaScript.
Coggle requires JavaScript to display documents.
Primate Origins of Human Behavior - Coggle Diagram
Primate Origins of Human Behavior
Introduction
Human behavior encompasses a wide range and heterogeneous range of phenomena
Evolutionary origins of higher order behavioral entities ad with the related methodological issues will be focused on
Social complexity results from the cumulative integration of more elementary units over time
Comparative behavioral primatology is the single most informative means at our disposal for reconstructing the evolutionary history of human behavior
This is because of the comparison of a behavioral phenomenon between humans and other primates that we share some of the building blocks with other species making them ancient
The study of fossilized hominin species provides crucial but highly fragmentary information on social behavior and mental processes, providing clues about behavior but information shrinks with time
Goes beyond artifacts, about 2.5 million years
Comparative primatology simultaneously reveals some of its present biological underpinnings
The biological bases of human social phenomena are often concealed by the extreme cross-cultural variability of behavior
There are no behavioral phenomena present in all cultures under the exact same form and meaning
There are highly polymorphic categories containing distinct cultural forms and meaning
Social phenomena in general were the products of cultural innovations and human biology can be ignored in their explanation
Human nature
The set of biological and psychological mechanisms shared by all human beings
Comparative primatology shows that many complex human social phenomena have an evolutionary history and hence biological underpinnings
Indicates that human nature does much more than setting general emotional and cognitive potentials
Generates social patterns
The Phylogenetic Deconstruction of Human Behavior
Many human behavioral phenomena have been the objects of detailed comparisons with other primates
This includes:
Emotions
Cognitive abilities (Social learning, theory of mind, self awareness, language,
Fundamental correlates of human cognitive abilities (culture, mortality)
General social processes (altruism, cooperation, contingent reciprocity)
Specific domains of social behavior (alloparenting, dominance and power, conflict resolution, sexual conflict, incest avoidance, sexuality, intergroup conflict)
Social relationships (pair-bonds, parent-offspring bonds, friendships)
Complex social patterns and social structure
Human behavioral phenomena may be classified into four categories:
Homologous traits
Homoplasious traits
Uniquely human adaptations
Composite traits
Homologies
Also known as homologous traits
Variants of the same trait present in two or more species and derived from the common ancestor of those species
Interspecific similarities reflecting common descent
The higher the degree of similarity between two species, the more recently they diverged from their last common ancestor
Used to infer the degree of genetic proximity between species and reconstruct an evolutionary tree
Used by molecular biologists to reconstruct phylogenies based on similarities in DNA or amino acid sequences
Degrees of similarity between species are proportional to how recently they diverged makes it possible to reverse the reasoning and infer homologous similarities from information on phylogeny
Knowing two species are descended from a common ancestor, one can see homologous similarities between them for a given trait
Useful in reconstruction of the evolution of behavior
Analyzed first in the 1940’s
Primarily concerned with the evolution of stereotyped behavior sequences
Later used to study the evolution of communication signals and facial expressions in primates
Traits homologous between humans and all other primate species were likely present in the ancestral species from which all primates originate
Homologies between humans and their two closest relatives, chimpanzees and bonobos likely characterized their last common ancestor some 6 to 7 million years ago
Identifying homologies between humans and the members of various primate taxons provides a way of going back in the evolution of the primary lineage
Homoplasies
There are similarities that evolved independently in distinct species in response to similar selective pressures and hence have a common adaptive function
Homoplasious similarities between humans and other species provide information about the initial adaptive function of the corresponding human trait
If the adaptive function of a trait observed in a number of different species is well established, it is possible to infer that the human version of the trait had a similar initial function
Can include polygyny, the formation of stable sexual bonds between one male and two or more females
Human Adaptations
Traits that are uniquely human and evolved in response to selective pressures of their own
Comprises, for example, of monogamous pair bonding in the context of large multimale-multifemale groups
Composite Traits
The emergent products of various combinations of the first three categories
Three-subclasses of composite traits:
Nonexclusive, which are human traits also observed in other primate species but under cognitively and socially much simpler forms
Exclusive, which are traits that are found only in humans
Cognitively generated, which result from the combination of old primate components with new cognitive abilities in the course of human evolution
The Incest Taboo
All humans have rules describing rules around sexual relations between close relatives
Universal proscription of incest between parts and offspring, grandparents and grand offspring and between siblings
Beyond that the types of unions considered incestuous varies
The cultural diversity of incest rules meant that the incest taboo could not have any biological underpinning and hence was a cultural creation
The very existence of a taboo was interpreted by many as implying that such a proscription must have been created to counter a natural tendency for committing incest
All primate species also avoid mating with their close kin despite no institutionalized rule against it
Strongly suggests that the incest taboo is a cultural construct derived from the natural tendency to avoid incest and that both phenomena have a common biological foundation
The following principles apply
Nonhuman primates recognize some of their kin as they treat them preferentially
Includes grooming them and tolerate them at food sites
The domain of kin recognition includes the mother, offspring, siblings, grandparents, and grand offspring with aunts, nieces, and nephews being in a grey zone
They only recognize genetic relatedness as high levels of developmental familiarity and maybe physical similarities
Inbreeding among close kin reduces an organisms reproductive success by reducing its fecundity or its offsprings chances of survival
Called inbreeding depression
Either the males, females, or sometimes both disperse from their birth place around puberty, limiting opportunities for incest
Among sexually mature individuals in the same group, mating is avoided among kin, which is a part of kin recognition
When sexual interactions between close kin do occur, they are performed mostly by immature individuals and in a behaviorally atypical manner
Incest avoidance appears to be mediated through correlates of close kinship bonds
Can include familiarity, intimacy, and attachment
Ie humans raised together develop an absence of erotic feelings, coined the Westermarck effect
Male primates seem less motivated than females to avoid incest
Males often initiate it
May be because the mother performing parental care, so the costs of reproductive failure due to inbreeding depression are higher for them than the fathers
Sexual avoidance between close kin is clearly documented among homosexual female macaques
This shows that developmental familiarity inhibits both heterosexual and homosexual sexual activity
Suggests these principles in primates show that they were a part of humankind’s primate legacy
Also constituted the universal biological substrate upon which hominins elaborated symbolically mediated rules about incest avoidance
Thus the existence of an incest taboo do not imply that humans have natural tendencies to engage in such behaviors
Rules and morality originated in the behavioral recurrences of our primate forebears and later grew in complexity in the symbolic realm
The diversity of cultural rules about incest, rather than negating the biological foundation of the incest taboo, shows that hominins modulated that biological heritage in relation to different:
Subsistence economies
Marriage practices
Kinship systems
Etc
Patrilineal Kinship Networks
Illustrates how primate studies help understand the origins of particularly complex social phenomena
Humans are those in which kinship has the most important impact on the structuration of social life
Humans exhibit the most extensive domain of kin recognition in the animal world
Humans live in large multimale-multifemale groups spanning three to four generations, recognizing kin in both mothers side and fathers side
Differentiate primary kin, secondary kin, tertiary kin, quaternary kin, and more distant kin
Because kinship fosters mutualistic cooperation it is a major factor in both the formation of social bonds and the patterning of social structure
Kinship of nonhuman primates
Varies in relation to group composition and dispersal patterns
Species that form large multimale-multifemale groups exhibit the most extensive domains of kin recognition but the latter are limited
These species may be divided into two categories according to their dispersal pattern:
Females stay and breed in their natal group where
Or the males who are philopatric and the females who leave
Dispersal patterns determine which kin live together and have opportunities to recognize one another
Two processes are involved:
Through proximity to her mother, the female spends different amounts of time and accumulates varying levels of familiarity with her mother’s mother, sister, etc
The female is in a position to differentiate the characteristics of the relationship her mother maintains with each of those kin
Observational and experimental studies indicate that while matrilinear kin recognition is widespread, patrilinear kin recognition is limited
In female philopatric species a female recognizes a substantial fraction of her matrilinear kin
Kin recognition depends on the existence of lifetime bonds between mothers and daughters and involved familiarity and association-based processes
The recognition of matrilineal kin is also observed in male philopatric species, such as chimpanzees and bonobos, but female dispersal usually limits the domain of kin recognition to mother-offspring dyads and maternal siblings
Patrilinear kinship is absent or extremely limited in female philopatric species for two reasons
Males and females have several short-term mating partners so fathers and offspring cannot recognize each other from long-term association between father and mother
Male dispersal entails that males do not grow up with their patrilinear kin and cannot recognize them
The Evolution of Patrilinear Kinship
Matrilinear kinship is widespread in nonhuman primates
Suggests that the psychological and social mechanisms were an integral part of our evolutionary heritage
Was present immediately after the pan-Homo split
The absence of extensive patrilinear kinship indicates that it evolved after the pan-homo split
The recognition of kinship along the paternal line expanded the domain of kin recognition and the impact of kinship on social life
Patrilinear kinship structures may affect several fundamental aspects of social life, including group membership and status transmission
Patrilineal kinship networks evolved in hominins
Extensive networks of matrilineal kinship in primates are the emergent products of the cooccurrence of more elementary features that have their own biological underpinnings and evolutionary history
The multimale-multifemale composition of social groups
Female philopatry, producing extensive matrilines
Male emigration
Lifetime bonds between mothers and daughters
Familiarity based kin recognition processes centered on the mother
Cooperative activities among females
The existence of kinship biases in the patterning of cooperation
When these traits occur in the same species, they form matrilineal kinship structures
Patrilineal kinship is the mirror of matrilinear kinship, with these trait co-occuring in the same species
A multimale-multifemale group composition
Male philopatry and its correlate, extensive patrilinies
Female emigration
Enduring father-son bonds
Familiarity-based kin recognition processes centered on the father
Cooperative activities among males
Kinship biases in cooperation
Only co-occur in humans, but chimpanzees conduct all of these except 4
Information about matrilineal kinship in primates also sheds light on the origins of some basic behavioral correlates of patrilineal kinship networks
Many female philopatric species show matrilineal dominance hierarchies in which females rank below their mothers
Shows a pattern of maternal favoritism
Sons may inherit their mothers status but cannot pass it, meaning status transmission is a unisexual/unilineal process
Matrilineal dominance orders stems from the factors generating matrilineal kinship, and factors like
The existence of stable dominance relationships among females
A consistent pattern of efficient maternal favoritism
The application of this model of status transmission to a situation of male philopatry, in which coresident males form a status order and fathers favor their sons, generates a pattern of patrilineal status transmission , a well documented and uniquely human phenomenon
Culture
Exemplifies the category of cognitively generated composite traits
Traits that emerged from primate components merging with new or enhanced cognitive abilities
The human capacity for culture rests on two categories of cognitive abilities underlying the capacity to invent new behaviors and the capacity to learn by observing or listening to others
When an individual’s innovation is adopted by others and spreads, it becomes a part of the culture
Innovations and social learning are adaptive
Innovativeness diversifies the means through which individuals can satisfy biological needs such as securing food
With social learning it allows animals to bypass individual trial and error learning and benefit from the inventive capacity of others
Two major properties of human culture
Ideational content
Cumulative character
Symbolic capacity the cultural repertoires of human groups includes ideas, beliefs, and meanings in addition to objects and techniques
Culture in humans is both behavioral and ideational
Human culture is cumulative in the sense that it commonly modifies prior innovations and combine distinct ones to create new and more complex patterns which will be modified and mixed to generate a new cultural state
Because the exact contents of innovations vary substantially between groups in relation to prior innovations, constraints imposed by the socioecological environment, and the vagaries of individual imagination, cultural evolution translates into the progressive diversification of groups in all behavioral domains, from clothing styles to language to political systems to religious beliefs.
The Primate Origins of Culture
We share some fundamental components of the cultural capacity with other species
Nonhuman primates possess the two basic requirements for culture:
Innovate
Observe in others
Evidence for cultural traditions in primates comes from studies documenting between-group behavioral differences not attributed to habit
the percentage of cultural differences between populations increased with geographic distance
Some cultural innovations have social purposes
Cultural differences between populations of the same species are documented in other primates
Chimpanzees and orangutans stand out as exhibiting more distinct traditions
There are distinct differences between human and nonhuman culture
The cultural repertoires of other species is extremely limited compared to the situation in humans and culture is neither ideational nor cumulative
The enhancement social learning abilities in the course of human evolution has played a role in the advent of the distinct properties of human culture
Social learning encompasses a large array of cognitive processes including
Stimulus enhancement
Emulation
Imitation
Teaching
Social learning origins are in intense debate and have implications for understanding the evolution of human culture
various experimental lines of evidence indicate that chimpanzees may not only emulate, but also imitate, depending on the circumstances
The Evolution of Human Behavioral Complexity
Many uniquely human traits appear to be original combinations of elements otherwise present in other primate species
The configurations are new, but their components are not
Other distinctly human traits evolved when new or enhanced cognitive abilities merged with old primate traits, with this generating new possibilities
The two basic components of the capacity for culture, innovativeness and social learning, transformed in human evolution because of new cognitive abilities that brought about important distinctive properties of human culture
The cognitive enhancement principle also helps explain the evolution of particularly complex and uniquely human social phenomena (ie marital arrangements)
The moral rules of conduct and the normative character of human sociality appear to have originated in the institutionalization of simple recurrences and regularities in the behavior of nonhuman primates
Such as the avoidance of incest in primates
The same principle applies to the evolutionary origins of the moral dimension of social reciprocity
The origins of behavioral universals in humans
In nonhuman primates, social acts and social activities and social patterns exhibit very little cultural variation
Being nearly a-cultural, they are most often monomorphic
All social activities and social patterns that constituted the baseline of hominin sociality progressively and cumulatively evolved into culturally polymorphic categories each containing distinct cultural forms fulfilling similar social functions