We classified papers according to whether they involved analysis of secondary data sets gathered for other purposes. The number of papers involving such secondary analysis increased sharply through the study period, whereas those involving primary data did not see Supplementary material. Comparative analyses also increased significantly over time, but not faster than the overall growth in paper numbers. Some examples of popular research questions in our database of recent HBE papers.
To summarize, the data suggest that HBE has changed measurably in the period since Some of the changes in this period represent continuations of trends already incipient before, such as the expansion away from foraging and foragers toward reproduction and other types of population Winterhalder and Smith Much of the growth has come from the adoption of HBE ideas by researchers based in departments of psychology, and, to a modest extent, other social sciences such as demography, public health, economics, and sociology.
This is concomitant with the increasing focus on large-scale industrialized societies, as well as changes in methodology. Anthropologists often work alone or in small teams to gather special-purpose, opportunistic data sets from a particular field site, and many of the pioneering HBE studies were done in this way. In demography, public health, and sociology, by contrast, research tends to be based on very large, systematically collected, representative data sets, such as censuses, cohort, and panel studies, which are designed with multiple purposes in mind.
Particular researchers can then interrogate them secondarily to address their particular questions. We also note the increase in the number of comparative studies. Comparative methods albeit usually comparing related species rather than populations of the same species have been a strong feature of BE since the outset or before, Cullen , and thus this is a natural development for HBE.
HBE comparative studies use existing cross-cultural databases Quinlan , integrate multiple ethnographic or historical sources Brown et al. In this section, we discuss what we see as the strengths, weaknesses, opportunities, and open questions for HBE as a paradigm. This is inevitably more of a personal assessment than the preceding sections, and we appreciate that not everyone in the field will share our views. The first obvious strength of HBE is vitality. As Darwinians, it comes naturally to us to assume that something that is increasing in frequency has some beneficial features.
Thus, the fact that the number of recognizably HBE papers per year found by our search strategy has doubled in a decade, and that there are more and more adopters outside of anthropology, indicates that a range of people find an HBE approach useful.
Where does this utility spring from? In part, it is that HBE models tend to make very clear, a priori predictions motivated by theory. The same cannot be said of all other approaches in the human sciences, and, arguably, the more we complicate behavioral ecological models by including details about how proximate mechanisms work, the more this clarity tends to disappear. Whether we are considering when to have a first baby Nettle , what the effects of having an extra child will be in different ecologies Lawson and Mace , whether to marry polygynously, polyandrously, or monogamously Fortunato and Archetti ; Starkweather and Hames , or which relatives to invest time and resources in Fox et al.
HBE has also demonstrated the generality of certain principles, such as the fact that male culturally defined social success is positively associated with reproductive success in many different types of society, albeit that the slope of the relationship differs according to features of the social system Irons ; Kaplan and Hill ; Borgerhoff Mulder ; Hopcroft ; Fieder and Huber ; Nettle and Pollet A related strength of HBE is its broad scope.
HBE models can apply to many kinds of behavioral decision in principle, all kinds and in all kinds of society. It is relatively rare in the human sciences for the same set of predictive principles to apply to variation both within and between societies and to societies ranging from small-scale subsistence populations to large-scale industrial states, but HBE thinking about, for example, reproductive decisions has exactly this scope Nettle ; Sear and Coall This would be a strength indeed, even without the crucial additional feature that the explanatory principles invoked are closely related to those that can be applied to species other than our own.
Thus, HBE brings a relative conceptual coherence to the study of human behavior, a study that has traditionally been spread across a number of different disciplines each with different conceptual starting points. Another strength of HBE as we have defined it here is its relatively high ecological validity.
Much psychological research into human behavior relies on hypothetical self-reports and self-descriptions, or contrived experimental situations Baumeister et al. Although human behavioral ecologists use such techniques as their purposes require, at the heart of HBE is still a commitment to looking at what people really do, in the environments in which they really live, as a central component of the endeavor.
Measuring relationships between behavior and fitness-relevant outcomes across a broad range of environments, HBE has now amassed considerable evidence in favor of its core assumptions that context matters when studying the adaptive consequences of human behavior and that behavioral diversity arises because the payoffs to alternative behavioral strategies are ecologically contingent.
HBE is also characterized by increasing methodological rigor. The early phases of HBE were defined by exciting theoretical developments, as evolutionary hypotheses for human behavioral variation were first formulated and presented in the literature. However, conducting empirical studies capable of rigorously testing hypotheses derived from HBE theory presents a number of methodological challenges, not least because the human species is relatively long lived and rarely amenable to experimental manipulation.
These challenges are now being increasingly overcome, as HBE expands its tool kit to include new sources of data, statistical methods, and study designs. Some sources of secondary data have also enabled lineages to be tracked beyond the life span of any individual researcher, providing valuable new data on the correlates of long-term fitness e. Statistical methods have also become more advanced. Multilevel analyses are now routinely used in HBE research to deal with hierarchically structured data and accurately partition sources of behavioral variance at different levels e.
Phylogenetic comparative methods, which utilize information on historical relationships between populations, have become popular for testing coevolutionary hypotheses since they were first applied to human populations in the early s Mace and Pagel ; Mace and Holden , though debate remains about their suitability for modeling behavioral transmission in humans Borgerhoff Mulder et al.
Issues of causal inference are also being addressed with more sophisticated analytical techniques. For example, structural equation modeling and longitudinal methods such as event history analysis have enabled researchers to achieve greater confidence when controlling for potential cofounding relationships e. HBE researchers are also following wider trends in the social and natural sciences by exploring alternatives to classic significance testing, such as information-theoretic and Bayesian approaches for considering competing hypotheses Towner and Luttbeg For example, Gibson and Gurmu examined the effect of changes in land tenure from family inheritance to government redistribution on a population in rural Ethiopia, demonstrating that competition between siblings for marital and reproductive success only occurs when land is inherited across generations.
Finally, HBE has shown itself capable of topical innovation. A pertinent recent example is cooperative breeding typically loosely defined in HBE as the system whereby women receive help from other individuals in raising their offspring. The idea that human females might breed cooperatively had been around for several decades Williams , and began to be tested empirically in the late s and s e. HBE has now mined many of the rich demographic databases available for our species to test empirically the hypothesis that the presence of other kin members is associated with reproductive outcomes such as child survival rates and fertility rates.
These analyses typically find support for the hypothesis that women adopt a flexible cooperative breeding strategy where they corral help variously from the fathers of their children, other men, and pre- and postreproductive women Hrdy Though we see HBE as a strong paradigm, there are some important weaknesses of its current research to be noted. Our search revealed only 8 HBE papers in these journals 2. The vast majority of papers in our sample appeared in journals which never carry studies of species other than humans, and we know of rather few human behavioral ecologists who also work on other systems.
West et al. HBE is clearly not completely decoupled from the rest of BE see Machery and Cohen for quantitative evidence on this point. Parallel developments have occurred in the human literature, with the rise of adaptive studies of psychological mechanisms see e. Finally, we note that there has been a recent increase in interest in measuring natural selection directly in contemporary human populations Nettle and Pollet ; Byars et al.
This anchors HBE much more strongly to evolutionary biology in general. Despite these developments, we see the isolation of HBE from the rest of biology as a potential risk. We hope to see more behavioral ecologists start to work on humans, and more projects across taxonomic boundaries, in the future. Finally, we note the rather restricted topic base.
HBE has had a great deal to say recently about mating strategies, reproductive decisions, fertility, and reproductive success, but much less about diet, resource extraction, resource storage, navigation, spatial patterns of habitat use, hygiene, social coordination, or the many other elements involved in staying alive.
In part, this is because, as HBE expands to focus more on large-scale populations, it discovers that there are already disciplines economics, sociology, human geography, public health that deal extensively with these topics. It is in the general area of reproduction that it is easiest to come up with predictions that are obviously Darwinian and differentiate HBE from existing social science approaches.
Nonetheless, the explanatory strategy of HBE is of potential use for any topic where behavioral effort has to be allocated in one way rather than another, and thus we would hope to see a broadening of the range of questions addressed as HBE continues to grow.
At the moment, most HBE papers are published in journals that only carry papers that take an adaptive evolutionary perspective, not general social science journals. Thus, HBE is possibly as separated from other approaches to human behavior as it is from parallel approaches to the behavior of other species.
This may be because early proponents of HBE saw it as radically different from existing social science approaches to the same problems, by virtue of its generalizing hypothetico-deductive framework and commitment to quantitative hypothesis testing Winterhalder and Smith However, the social science those authors came into closest contact with was sociocultural anthropology, which is perhaps not a very typical social science see Irons for an account of the hostile reception of HBE within sociocultural anthropology.
Social scientists are united in the notion that human behavior is very variable and that context is extremely important in giving rise to this variation. These are commitments that HBE obviously shares. Much of social science is highly quantitative and, generally lacking the ability to perform true experiments, relies on multivariate statistical approaches applied to observational data sets to test between competing explanations for behavior patterns.
HBE is just the same, and indeed, since the millennium, has become much more closely allied to other social sciences, adopting the large-scale data resources they provide, as well as methodological tools like multilevel modeling, which they have developed to deal with these.
HBE employs a priori models based on the individual as maximizer, a position not shared explicitly by all social sciences. However, this approach is widespread in economics and political science. Indeed, it was economics that gave it to BE. The big difference between HBE and much of social science is the explicit invocation of inclusive fitness or its proxies as the end to which behavior is deployed.
This does not necessarily make it a competing endeavor, especially because what is measured in HBE is not usually fitness itself, but more immediate proxies. Rather, HBE models can often be seen as adding an explicitly ultimate layer of explanation, giving rise to new predictions and unifying diverse empirical observations, without being incompatible with existing, more proximate theories. Examples include the work of Geronimus on how African American women adjust their patterns of childbearing to the prevailing rates of mortality and morbidity in their neighborhoods Geronimus et al.
If the introductory sections of any of these papers were written from a more explicitly Darwinian perspective, they would look perfectly at home in a BE journal. The breaking down of the social science—natural science divide has long been held as desirable, but is not easy to achieve in practice. Social scientists have long lamented the fragmentation of their field into multiple disciplinary areas with little common ground e.
A related opportunity for HBE is the potential for applied impact. HBE models have the potential to provide new and practical insights into contemporary world issues, from natural resource management Tucker to the consequences of inequality within developed populations Nettle The causes and consequences of recent human behavioral and environmental changes including urbanization, economic development, and population growth are recurring themes in recent studies in HBE.
The utility of an ecological approach is clearly demonstrated in studies exploring the effectiveness of public policies or intervention schemes seeking to change human behavior or environments. HBE models clarify that human behavior tends to be deployed in the service of reproductive success, not financial prudence, health, personal or societal wellbeing Hill , an important insight that differs from some economic or psychological theories.
By providing insights into ultimate motivations and proximate pathways to human behavioral change, HBE studies can sometimes offer direct recommendations for the design and implementation of future initiatives Gibson and Mace ; Shenk ; Gibson and Gurmu Addressing contemporary world issues does, however, present methodological and theoretical challenges for HBE, requiring more explicit consideration of how research insights may be translated into interventions and communicated to policymakers and users Tucker and Taylor An open question for HBE is how the study of mechanism can be integrated into functional enquiry.
This is an issue for BE generally, not just the human case. It is important to understand the status of the behavioral gambit because it has sometimes been unfairly criticized see Parker and Maynard Smith In the natural world, individuals do not always behave optimally with respect to any particular decision because there are phylogenetic or mechanistic constraints on their ability to reach adaptive solutions.
However, in general terms, the only way to discover the existence of such departures from optimality is to have a theoretical model that shows what the optimal behavior would be and to test empirically whether individual behavior shows the predicted pattern.
Where it does not, this may point to unappreciated constraints or trade-offs and thus shed light on the biology of the organism under study. Thus, the use of the term gambit is entirely apt; the behavioral gambit is a way of opening the enquiry designed to gain some advantage in the quest to understand. It is not the end game. Where there is no sizable departure from predicted optimality, the ultimate adaptive explanation does not depend critically on understanding the mechanisms.
This does not mean the question of mechanism is unimportant, of course; mechanistic explanations must still be sought and integrated with functional ones. This is beginning to occur in some cases. In the field of human reproductive ecology, the physiological mechanisms involved in adaptive strategies are beginning to be understood Kuzawa et al.
Where there is a patterned departure from optimality, understanding the mechanism becomes more critical. Aspects of mechanism can then be modeled as additional constraints, which may explain the strategies individuals pursue. At a deeper level, though, this just raises further questions. Departures from optimality in one particular context raise such questions pervasively.
Issues such as the robustness, neural instantiability, efficiency, and developmental cost of different kinds of mechanisms become salient here, and many apparently irrational quirks of behavior become interpretable as side effects of evolved mechanisms whose overall benefits have exceeded their costs over evolutionary time Fawcett et al. However, we would still argue that the best first approximation in understanding a question is to employ the behavioral gambit to generate and test simple optimality predictions, even though an understanding of mechanism will be essential for explaining why these may fail.
Although the issue of how incorporation of mechanism changes the predictions of BE models is a general one, in the human case, it has been discussed in particular with reference to transmitted culture because this is a class of mechanism on which humans are reliant to a unique extent Richerson and Boyd Transmitted culture refers to the behavioral traditions that arise from repeated social learning.
Social learning can be an evolutionarily adaptive strategy, and the equilibrium solutions reached by it will often be the fitness-maximizing ones under reasonable assumptions Henrich and McElreath After all, if reliance on culture on average led to maladaptive outcomes, there would be strong selection on humans to rely on it less.
Indeed, there is evidence that humans tend to forage efficiently for socially acquired information, using it when it is adaptive to do so Morgan et al. Thus, we would argue that culture can be treated, to a first approximation, just like any other proximate mechanism: that is, it can be set aside in the initial formulation of functional explanations Scott-Phillips et al.
The fact that in this case it is culture by which women acquire them, rather than genes or individual learning, does not affect this conclusion or the data needed to test it. However, the quirks of how human social learning works may well explain some nonadaptive taboos that are found alongside the adaptive ones, which are in effect carried along by the generally adaptive reliance on social learning.
Thus, although the behavioral gambit can be used to explain the major adaptive features of these taboos, an understanding of the cultural mechanisms is required to explain the details of how the observed behavior departs in subtle ways from the optimal pattern. Culture may often lead to maladaptive side effects in this way Richerson and Boyd Although its general effect is to allow humans to rapidly reach adaptive equilibria, nonadaptive traits can be carried along by it, and, compared with other proximate mechanisms, it produces very different dynamics of adaptive change.
A final open question is the extent of human maladaptation. Humans have increased their absolute numbers by orders of magnitude and colonized all major habitats of the planet, so they are clearly adept at finding adaptive solutions to the problem of living.
However, there are also some clear cases of quite systematic departures from adaptive behavior. Perhaps most pertinently, the low fertility rate typical of industrial populations still defies a convincing adaptive explanation, despite being a longstanding topic for HBE research see Borgerhoff Mulder ; Kaplan et al.
There are patterns in the fertility of modernizing populations, which can be readily understood from an HBE perspective: parents in industrialized populations who have large families suffer a cost to the quality of their offspring, particularly with regard to educational achievement and adult socioeconomic success, so there is a quality—quantity trade-off Lawson and Mace Moreover, the reduction in fertility rate is closely associated with improvement in the survival of offspring to breed themselves, so that, as the transition to small families proceeds, the probability of having at least one grandchild may remain roughly constant Liu and Lummaa However, despite all this, it remains the case that people in affluent societies could still have many more grandchildren and great-grandchildren by having more children, and yet they do not Goodman et al.
Any explanation of the demographic transition must, therefore, invoke some kind of maladaptation or mismatch between the conditions under which decision-making mechanisms evolved and those under which they are now operating.
Our review has shown that HBE is a growing and rapidly developing research area. HBE is being applied to more questions in more human populations with better methods than ever before. Our hope is that HBE will inspire more behavioral biologists to work on humans, for whom a wealth of data is available, and more social scientists to adopt an adaptive, ecological perspective on their behavioral questions, thus adding a layer of deeper explanations, as well as generating new insights.
Supplementary material can be found at Supplementary Data. Confidence of paternity, divorce, and investment in children by Albuquerque men. Evol Hum Behav. Google Scholar. Bardsley N. Dictator game giving: altruism or artefact? Exp Econ. Psychology as the science of self-reports and finger movements: whatever happened to actual behavior? Perspect Psychol Sci. Hum Nat. Bock J. Learning, life history, and productivity. Borgerhoff Mulder M.
On cultural and reproductive success: Kipsigis evidence. Am Anthropol. Behavioral ecology in traditional societies. Trends Ecol Evol.
Behav Ecol Sociobiol. The demographic transition: are we any closer to an evolutionary explanation? The intergenerational transmission of wealth and the dynamics of inequality in pre-modern societies. Cultural macroevolution and the transmission of traits. Evol Anthropol. Bulled NL Sosis R. Examining the relationship between life expectancy, reproduction, and educational attainment.
Are affines treated as biological kin? Curr Anthropol. Buss DM. Evolutionary psychology: a new paradigm for psychological science. Psychol Inquiry. Natural selection in a contemporary human population. Early stress predicts age at menarche and first birth, adult attachment, and expected lifespan.
Testing evolutionary hypotheses with demographic data. Popul Dev Rev. Provisioning offspring and others: risk-energy trade-offs and gender differences in hunter-gatherer foraging strategies. Natural and sexual selection in a monogamous historical human population. Cronk L. Human behavioral ecology.
Annu Rev Anthropol. Cullen E. Adaptations in the kittiwake to cliff nesting. An introduction to behavioural ecology. Chichester : Wiley-Blackwell p. Google Preview. Davis J Werre D. Advanced search. Skip to main content Thank you for visiting nature. Atom RSS Feed Behavioural ecology Definition Behavioural ecology is the study of behavioural interactions between individuals within populations and communities, usually in an evolutionary context.
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