In the absence of the eye-witness information about present-day societies that sociologists use to define cultures, or the written information about ancient societies that historians use, the main corpus of information that archaeologists use to describe and define ancient cultures is confined to the material evidence. The term ‘material evidence’ refers to all traces that are left by past people. This includes artefacts (portable objects, e.g., pottery, weapons) and features (non-portable objects) like postholes, hearths, floors, walls, and ditches. Environmental and organic remains, like soils, sediments and human skeletons are also part of the material evidence. Archaeologists focus on the arrangement and relation among these different material remnants in order to detect patterns in the behaviour of past humans and interpret these practices. For their interpretation, the comparison with and the use of concepts from other disciplines like sociology, ethnology, and history play a major role. History is especially important for archaeological research during historic times when the written evidence and the archaeological evidence temporally overlap31,32,33.

The general observation that single objects and features as well as whole assemblages differ from each other in execution and style not only over time, but also on a geographical scale led to their classification into groups which are called ‘cultures’31,32. Usually the definition of an archaeological culture is based on only parts of the material object assembly. For prehistory stone tools and pottery are of crucial importance in this respect, since they constitute the most abundant and the most rapidly changing artefact groups33. Some archaeological cultures have been completely constructed on the basis of pottery typology and only afterwards the rest of the material assemblage was loosely fitted into this framework. A good example is the Early Neolithic in the Balkans. Here small changes in the quantitative composition of painted pottery as well as national borders have led to the construction of various archaeological cultures, like the Starčevo Culture in Serbia or the Karanovo Culture and Western-Bulgarian-Painted-Pottery Culture in Bulgaria with their numerous regional variants and sub-groups34,35. The case example of the Balkans illustrates that the distinction into different archaeological cultures or groups is relative and that there exists no universal explanation for what stands behind an archaeological culture. In particular, the question of whether a distinct material group/culture as defined by archaeologists also represented a meaningful entity in the past is a matter of debate and needs to be evaluated on a case-by-case basis.

Archaeological cultures are predominantly named after two systems: 1. Either they are named after a ‘type-site’, like the Michelsberger Culture36, or 2. their designation derives from a ‘type-artefact’ or ‘index-fossil’ as is the case with the Bell Beaker Complex37.Both systems are based on the assumption that the given diagnostic part of the evidence suffices to name the phenomenon as a whole. A third option for naming an archaeological culture consists in adopting a historically attested name, by transfering it to a materially discernible group, like Philistine38,39 or Viking40. This “translation” can be based on written sources that are contemporaneous with the archaeological culture or postdate it (or both). The general idea that both the written sources and the material evidence depict the same group of people is driven mainly by their spatial equivalence. If and how the historical records about a certain group of people and the archaeological record are connected with each other needs again to be investigated on a case-by-case basis. These questions about identities and ethnicites in the past are one of the major fields of research in ancient studies40,41,42,43,44,45,46. It also needs to be taken into account here that most identifications of a historically attested group and an archaeological one and the corresponding naming of the one after the other date back to the 19th and early 20th centuries42,47.

The concept of defining cultures in archaeology was an integral part of the development of cultural history by archaeologists and anthropologists alike in North America and Europe in the 19th century33. Politically its origins are connected with the formation of modern national states and national identities in Europe during the 19th and 20th centuries47. The intellectual construction of a common history shared by the inhabitants of a country and putatively stretching back into prehistoric times was part of this process. Within this context of emerging national consciousness, which aimed at setting our own apart from the other, the German archaeologist Gustaf Kossinna established his ‘settlement archaeology’ (original: ‘Siedlungsarchäologie’)42,47. In his 1911 book The Origin of the Germans (original: Die Herkunft der Germanen) he stated: “Sharply defined archaeological culture-provinces coincide at all times with quite definite peoples or tribes.” (as translated in Childe 1956, 2848; original: Kossina 1911, 349: “Scharf umgrenzte archäologische Kulturprovinzen decken sich zu allen Zeiten mit ganz bestimmten Völkern oder Völkerstämmen.”). As a consequence, cultures defined via the archaeological record were perceived as being the material remnants of closed ethnic groups. For Kossinna (and others) these ethnic groups were distinct peoples who shared the same blood (or genes). During the 1930s and 1940s, fascist archaeology instrumentalised this notion to justify racial ideologies by adding a prehistoric perspective. By tracing Germans as an archaeological culture back into the Neolithic and over vast regions of Central and Eastern Europe, National Socialist archaeologists argued for ethnic cleansing and expansionist warfare. They were convinced of the biological superiority of their own race over other people and traced this superiority far back into prehistoric times. Kossinna’s ‘settlement archaeology’ not only shaped German archaeology up to the 1950s, but continued to exercise its influence well beyond. The general method of equating material culture with ethnicity became commonplace. In Britain, the main figure connected with this method is Vere Gordon Childe42. His work contributed greatly to cementing the static thinking that archaeological cultures equate to ethnic groups with shared ancestries.

In the decades following World War II, cultural studies moved away from the idea of the association between culture and ‘blood’. On the contrary, culture and ethnicity were perceived as dynamic, subjective and artificial. At the same time, Central European archaeological research became rather antiquarian. Archaeologists tended to collect and classify artefacts, but avoided far-reaching interpretations. Consequently, archaeological cultures became an abstract and mostly academic concern50. They continued to be used as a tool for classifying the material evidence and the undertone of equating material culture with ethnicity was never entirely dispelled – in part due to the lack of broad and open debate about the concept of culture in archaeology51.

With the advent of the ‘New Archaeology’ or ‘Processual Archaeology’ in the 1960s and 1970s, Anglo-American archaeological research shifted to functionalist questions of past social-cultural systems that understood culture (not cultures) as a means of adaptation to external factors and conditions imposed by the surrounding environment42,52,53.

The debate on prehistoric cultures and ethnicity only re-entered archaeology in the 1990s and early 2000s. By openly discussing how to trace ethnicity or identity in the archaeological record and by reviewing previous research, archaeologists developed a more nuanced understanding of the old argument about whether pots equal people. Whether and under which conditions an archaeologically discernible group can be viewed as the material remnants of a once living group of people who were connected via the same beliefs, social practices, ancestry, or in any other way needs to be investigated individually and will rarely stand without contradiction. In spite of all inherent problems, material groups in archaeology are often still called cultures. Yet the concept of cultures, including its whole history, seems to be so deeply rooted in archaeology that what it means (material group) and what it may or may not imply is widely if tacitly understood33,42,43,44,47,50,54. In some cases the term culture has been replaced by terms that the respective researchers believe to be a better description of the observed archaeological patterns55, as for example with the Bell Beaker Complex or Phenomenon37,56. The problematic nature of archaeological groupings has already been pointed out in archaeogenetic publications, for example, in the supplementary section of The Beaker phenomenon and the genomic transformation of northwest Europe by Olalde et al.28.

The use of archaeological cultural designations in genetic studies

If geneticists use names originating from the field of archaeology for genetic clusters, an inevitable by-product is to transfer at least part of the name’s archaeological meaning into the genetic study. Giving groups that have been identified through a completely different line of evidence – in this case material culture and genomics – the same or related names results in their conflation and the archaeological designations risk becoming reified in genetic terms (and vice versa). Even if there is a striking correspondence between a genetically defined cluster and the archaeological culture that the sampled individuals are associated with, they remain two different phenomena, identified by different methods with different criteria, which may or may not have some connections to each other. In principle, there does not need to be any clear relationship between the two at all.

This scenario has been shown in a recent genetic study. Here individuals from Iberia and Central Europe displaying, archaeologically speaking, the same cultural affiliations – both would be grouped under the term Bell Beaker Complex – are genetically rather heterogeneous28. Another interesting case is the so-called Srubnaya_outlier: An individual who, archaeologically speaking, belongs to the Srubnaya culture turned out to be genetically very distinct from the other individuals with the same archaeological cultural affiliation17.

These two examples illustrate that only further analysis and discussion on a case-by-case basis can clarify the likelihood and nature of the association between a material and a genetic group. Even a specific pattern of relatedness between an archaeological culture and a genetic cluster does not in itself prove that this archaeological culture was a meaningful human entity in the past, but invites further reflection and investigation.

Despite these concerns, we do not feel it is appropriate to abandon the practice of comparing a genetic cluster and an archaeological culture. Correlations between these, if they exist, are of profound interest, as it is not irrelevant if people who shared one archaeological culture (considered as the material expression of parts of shared social practices and traditions of particular groups of actors) also shared a similar genetic makeup, and therefore ancestry. Such convergences might help shed light on the nature of an archaeological culture, how it spread, and what may lie hidden behind a group of similar objects and/or practices. They can help to build a bridge from the material record back to the people who created and used these objects. The opposite is of course equally true, when people who did not share a similar genetic makeup chose to adopt similar cultural practices. We only insist here on a clear distinction between the two kinds of evidence, the genetic and the archaeological.

In most cases, scientists publishing genetic studies are fully aware of the general difference between a genetic and an archaeological group. This may explain why there has so far been no public discussion about the nomenclature of genetic clusters. Although it may simply not cause major misunderstandings at the source, where the data are generated, the casual conflation of archaeological and genetic classifications has considerable potential to confuse subsequent use of the data and its interpretation by third parties.

The young field of archaeogenetics needs to be as deliberate as possible in terminology to avoid falling into the pitfalls of earlier approaches to archaeological cultures and related interpretations. Even as an increasing number of archaeologists is moving away from the concept of material cultures in archaeology as a whole, it may seem unwise to expand it now to other disciplines33,57. Another related issue needs to be taken into consideration here, but lies beyond the scope of this paper, that is the political instrumentalisation of names for archaeological groups, especially those derived from historical (written) sources. Varying political agents still (ab)use archaeological group designations as ethnic labels with genealogical implications to underpin their respective agendas58.