Human behavioral ecology (HBE) or human evolutionary ecology applies the principles of

evolutionary theory Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

and

optimization Mathematical optimization (alternatively spelled ''optimisation'') or mathematical programming is the selection of a best element, with regard to some criterion, from some set of available alternatives. It is generally divided into two subfi ...

to the study of

human behavior Human behavior is the potential and expressed capacity ( mentally, physically, and socially) of human individuals or groups to respond to internal and external stimuli throughout their life. Kagan, Jerome, Marc H. Bornstein, and Richard M. ...

al and

cultural diversity Cultural diversity is the quality of diverse or different cultures, as opposed to monoculture, the global monoculture, or a homogenization of cultures, akin to cultural evolution. The term "cultural diversity" can also refer to having different c ...

. HBE examines the

adaptive Adaptation, in biology, is the process or trait by which organisms or population better match their environment Adaptation may also refer to: Arts * Adaptation (arts), a transfer of a work of art from one medium to another ** Film adaptation, a ...

design of traits,

behaviors Behavior (American English) or behaviour (British English) is the range of actions and mannerisms made by individuals, organisms, systems or artificial entities in some environment. These systems can include other systems or organisms as wel ...

, and life histories of humans in an

ecological Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

context. One aim of modern human behavioral ecology is to determine how ecological and

social Social organisms, including human(s), live collectively in interacting populations. This interaction is considered social whether they are aware of it or not, and whether the exchange is voluntary or not. Etymology The word "social" derives from ...

factors influence and shape behavioral flexibility within and between human

populations Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...

. Among other things, HBE attempts to explain variation in human behavior as adaptive solutions to the competing life-history demands of growth, development, reproduction, parental care, and mate acquisition. HBE overlaps with

evolutionary psychology Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regards to the ancestral problems they evol ...

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

cultural ecology Cultural ecology is the study of human adaptations to social and physical environments. Human adaptation refers to both biological and cultural processes that enable a population to survive and reproduce within a given or changing environment. Thi ...

, and

decision theory Decision theory (or the theory of choice; not to be confused with choice theory) is a branch of applied probability theory concerned with the theory of making decisions based on assigning probabilities to various factors and assigning numerical ...

. It is most prominent in disciplines such as

anthropology Anthropology is the scientific study of humanity, concerned with human behavior, human biology, cultures, societies, and linguistics, in both the present and past, including past human species. Social anthropology studies patterns of be ...

and

psychology Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries between ...

where

human evolution Human evolution is the evolutionary process within the history of primates that led to the emergence of '' Homo sapiens'' as a distinct species of the hominid family, which includes the great apes. This process involved the gradual development o ...

is considered relevant for a holistic understanding of

or in

economics Economics () is the social science that studies the production, distribution, and consumption of goods and services. Economics focuses on the behaviour and interactions of economic agents and how economies work. Microeconomics analyzes ...

where

self-interest Self-interest generally refers to a focus on the needs or desires (''interests'') of one's self. Most times, actions that display self-interest are often performed without conscious knowing. A number of philosophical, psychological, and economi ...

methodological individualism In the social sciences, methodological individualism is the principle that subjective individual motivation explains social phenomena, rather than class or group dynamics which are illusory or artificial and therefore cannot truly explain marke ...

, and maximization are key elements in modeling behavioral responses to various ecological factors.

Evolutionary theory

Human behavioral ecology rests upon a foundation of evolutionary theory. This includes aspects of both general evolutionary theory and established middle-level evolutionary theories, as well. Aspects of general evolutionary theory include: *

Natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Charle ...

, the process by which individual

organism In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...

s with favorable traits are more likely to survive and

reproduce Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual org ...

. *

Sexual selection Sexual selection is a mode of natural selection in which members of one biological sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of t ...

, the

theory A theory is a rational type of abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with such processes as observational study or research. Theories may be s ...

that competition for mates between individuals of the same sex results in differential mating and reproduction. *

Kin selection Kin selection is the evolutionary strategy that favours the reproductive success of an organism's relatives, even when at a cost to the organism's own survival and reproduction. Kin altruism can look like altruistic behaviour whose evolution i ...

, the changes in

gene frequency In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

across generations that are driven at least in part by interactions between related individuals. *

Inclusive fitness In evolutionary biology, inclusive fitness is one of two metrics of evolutionary success as defined by W. D. Hamilton in 1964: * Personal fitness is the number of offspring that an individual begets (regardless of who rescues/rears/supports them ...

, the sum of an individual's own reproductive success, (natural and sexual selection), plus the effects the individual's actions have on the reproductive success of that individual's kin, (kin selection). Middle-level evolutionary theories used in HBE include: *The theory of

parental investment Parental investment, in evolutionary biology and evolutionary psychology, is any parental expenditure (e.g. time, energy, resources) that benefits offspring.Clutton-Brock, T.H. 1991. ''The Evolution of Parental Care''. Princeton, NJ: Princeton ...

, which predicts that the sex making the largest investment in

lactation Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The proces ...

, nurturing and protecting

offspring In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This ca ...

will be more discriminating in mating and that the sex that invests less in offspring will compete for access to the higher investing sex. *

Parent–offspring conflict Parent–offspring conflict (POC) is an expression coined in 1974 by Robert Trivers. It is used to describe the evolutionary conflict arising from differences in optimal parental investment (PI) in an offspring from the standpoint of the parent an ...

, which predicts that because the genetic interests of parents and offspring are not identical, offspring will be selected to manipulate their parents in order to ensure higher investment, and that, conversely, parents will be selected to manipulate their offspring. *The theory of

reciprocal altruism In evolutionary biology, reciprocal altruism is a behaviour whereby an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar m ...

, a form of

altruism Altruism is the principle and moral practice of concern for the welfare and/or happiness of other human beings or animals, resulting in a quality of life both material and spiritual. It is a traditional virtue in many cultures and a core as ...

in which one organism provides a benefit to another in the expectation of future reciprocation. *The

Trivers–Willard hypothesis In evolutionary biology and evolutionary psychology, the Trivers–Willard hypothesis, formally proposed by Robert Trivers and Dan Willard in 1973, suggests that female mammals adjust the sex ratio of offspring in response to maternal condition, ...

, which proposes that parents should invest more in the sex that gives them the greatest reproductive payoff (grandchildren) with increasing or marginal investment. *

r/K selection theory In ecology, ''r''/''K'' selection theory relates to the selection of combinations of traits in an organism that trade off between quantity and quality of offspring. The focus on either an increased quantity of offspring at the expense of individ ...

, which, in

ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

, relates to the selection of traits in organisms that allow success in particular environments.

r-selected In ecology, ''r''/''K'' selection theory relates to the selection of combinations of traits in an organism that trade off between quantity and quality of offspring. The focus on either an increased quantity of offspring at the expense of individ ...

species – in unstable or unpredictable environments – produce many offspring, any individual one of which is unlikely to survive to adulthood, while

K-selected In ecology, ''r''/''K'' selection theory relates to the selection of combinations of traits in an organism that trade off between quantity and quality of offspring. The focus on either an increased quantity of offspring at the expense of indivi ...

species – in stable or predictable environments – invest more heavily in fewer offspring, each of which has a better chance of surviving to adulthood. *

Evolutionary game theory Evolutionary game theory (EGT) is the application of game theory to evolving populations in biology. It defines a framework of contests, strategies, and analytics into which Darwinian competition can be modelled. It originated in 1973 with John Ma ...

, the application of

population genetics Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and pop ...

-inspired models of change in gene frequency in populations to

game theory Game theory is the study of mathematical models of strategic interactions among rational agents. Myerson, Roger B. (1991). ''Game Theory: Analysis of Conflict,'' Harvard University Press, p.&nbs1 Chapter-preview links, ppvii–xi It has appli ...

. *

Evolutionarily stable strategy An evolutionarily stable strategy (ESS) is a strategy (or set of strategies) that is ''impermeable'' when adopted by a population in adaptation to a specific environment, that is to say it cannot be displaced by an alternative strategy (or set of ...

, which refers to a

strategy Strategy (from Greek στρατηγία ''stratēgia'', "art of troop leader; office of general, command, generalship") is a general plan to achieve one or more long-term or overall goals under conditions of uncertainty. In the sense of the "art ...

, which if adopted by a population, cannot be invaded by any competing alternative strategy.

Basic principles

Ecological selectionism

Ecological selectionism refers to the assumption that humans are highly flexible in their behaviors. Furthermore, it assumes that various ecological forces select for various behaviors that optimize humans' inclusive fitness in their given ecological context.

The piecemeal approach

The piecemeal approach refers to taking a reductionist approach as opposed to a

holistic Holism () is the idea that various systems (e.g. physical, biological, social) should be viewed as wholes, not merely as a collection of parts. The term "holism" was coined by Jan Smuts in his 1926 book ''Holism and Evolution''."holism, n." OED Onl ...

approach in studying human socioecological behavior. Human behavioral ecologists assume that by taking complex social phenomena, (e.g., marriage patterns, foraging behaviors, etc.), and then breaking them down into sets of components involving decisions and constraints that they are in a better position to create models and make predictions involving human behavior. An example would be examining marriage systems by examining the ecological context, mate preferences, the distribution of particular characteristics within the population, and so forth.

Conditional strategies

Human behavioral ecologists assume that what might be the most adaptive strategy in one environment might not be the most adaptive strategy in another environment. Conditional strategies, therefore, can be represented in the following statement: *In environmental context X, engage in adaptive strategy A. *In environmental context Y, engage in adaptive strategy B.

The phenotypic gambit

The phenotypic gambit refers to the simplifying assumption that

complex traits Complex traits, also known as quantitative traits, are traits that do not behave according to simple Mendelian inheritance laws. More specifically, their inheritance cannot be explained by the genetic segregation of a single gene. Such traits show ...

, such as behavioural traits, can be modelled as if they were controlled by single distinct alleles, representing alternate strategies. In other words, the phenotypic gambit assumes that "selection will favour traits with high fitness ...irrespective of the particulars of inheritance."

Modeling

Theoretical models that human behavioral ecologists employ include, but are not limited to: *

Optimal foraging theory Optimal foraging theory (OFT) is a behavioral ecology model that helps predict how an animal behaves when searching for food. Although obtaining food provides the animal with energy, searching for and capturing the food require both energy and t ...

, which states that organisms focus on consuming the most energy while expending the least amount of energy. *

Life history theory Life history theory is an analytical frameworkVitzthum, V. (2008). Evolutionary models of women's reproductive functioning. ''Annual Review of Anthropology'', ''37'', 53-73 designed to study the diversity of life history strategies used by differen ...

, which postulates that many of the

physiological Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...

traits and behaviors of individuals may be best understood in relation to the key maturational and reproductive characteristics that define the life course. * Sex allocation theory, which predicts that parents should bias their reproductive investments toward the offspring sex generating the greatest fitness return. *The

polygyny threshold model The polygyny threshold model is an explanation of polygyny, the mating of one male of a species with more than one female. The model shows how females may gain a higher level of biological fitness by mating with a male who already has a mate. The ...

, which suggests that

polygyny Polygyny (; from Neoclassical Greek πολυγυνία (); ) is the most common and accepted form of polygamy around the world, entailing the marriage of a man with several women. Incidence Polygyny is more widespread in Africa than in any o ...

is driven by female choice of mates who control more resources relative to other potential mates in the population.

References

{{Reflist

External links

The Human Behavioral Ecology Bibliography
– Maintained by Kermyt G. Anderson Demography Anthropology Behavioral ecology Behavioural sciences H Sociobiology