Natural origins of social essentialism: Ethnic groups,identities,and cultural transmission

Abstract

This paper argues that the term ‘social essence’ is overused in psychological research and includes instances that are not covered by the basic definition of an essentialist cognition with living beings. Imagining an essence of living beings is conceptualized as a meta-cognition that wraps up an exemplars' characteristics as a marker and assigns it a kind or species. This paper develops a framework of how social essentialism can be conceptualised to originate in natural contexts. Ethnic groups maintain a group identity that is defined by a set of diacritical markers and secured by a rule of endogamy, which functionally replicates the procreative pattern in animal species. This ‘functional homological’ relationship construes a group identity in the image of animal kinds. Thus construed, an ethnic identity appears as a natural given that safeguards the group’s cohesion and stability across generations. Hence, group-related essentialism primarily serves identity formation and provides a cognitive mechanism to distinguish the ingroup from outgroups. The intuition of an essentialised identity is perpetuated across generations by bio-social processes of enculturation. Such processes can explain an historically stable group essentialism, as well as group-biased judgements in former and contemporary societies without the need for innate sources of psychological essentialism.

Lineages

When I was invited to Israel some years ago, I had a casual conversation with my host about our families and children. It turned out that one of her sons had emigrated from Israel and married a girl of Catholic faith. While this fact did not sound extraordinary to me, she felt the need to add that she did not understand her son's decision not to marry a Jewish woman instead. Her comment baffled me for a moment because I knew her to be a politically liberal, cosmopolitan, and non-orthodox colleague. I was surprised by her allusion to religious affiliations, but what she meant was ethnic belonging and the fact that her grandchildren born by a Christian mother were not going to be Jewish according to the traditional matrilineal rule of descent (Chervyakov et al., 1997; Hartman & Hartman, 2001).

Besides expressing discontent with her son’s choice, her comment referred to two correlated pathways of essentialist thinking. First, she confirmed that in her opinion Jewish-ness has at least one essential characteristic that cannot be replaced, that is being born by a Jewish mother. Second, she attributed a Christian woman an essence of ‘Christian-ness'—incompatible with Jewish-ness—that cannot be shed. Attributing a distinct characteristic to her own group that an outgroup lacks, bears the mark of essentialist thinking. Essentialism can be observed in many situations, for example with friends identifying as Totonacs in Papantla, México. My probing question of whether an adopted infant from the Lacandon Maya in Chiapas could ever be considered a Totonac, was met with incredulity and the idea was ridiculed as nonsense.

Disclaimer: I use the term essentialism exclusively in the sense of a psychological projection on living beings and social targets. The term essentialism does not imply that natural kinds, living beings, or social groups possess something like an empirically identifiable substance of essence. The term ‘identity’ in the present context always means group-identity that by and large the members of a group share.

Some problems of essentialism in psychology

Psychological essentialism is a field of inquiry in social psychology that looks at the reasons of why people sometimes tend to attribute essential characteristics onto living beings or humans, that supposedly determine their membership in biological species or social categories. ¹ This projected essence is perceived as an invisible and causally agentic substance that appears to govern the identity of a living being along its life course (e.g. Atran et al., 1997). Somehow the idea of an essence of a living being resembles the idea of a vis vitalis, that is a “vital force” that philosophers hypothesized as driving the phenomena of life in former times.

A snake, for example, shows an elongated body, a split darting tongue, and a creeping movement. In other words, a snake has a lot of characteristics that an observer perceives in their entirety and that likely guides their frightened response. The intuition of essence posits that the bundle of co-occurring characteristics in a living being is not coincidental and linguistically wraps them up as snake-ness. Hence, an essentialist cognition is a meta-cognition that conjectures that what looks like a snake belongs to the kind of snakes.

An essence in the biological domain is imagined representing the inherent potential that an exemplar of a living kind, a species, or a life form has. The most important features of perceiving a natural essence are immutability, that is an animal’s essence and category belonging cannot be manipulated or altered by outside interference, a cat is still seen as a cat even if it is disguised as a dog; discreteness, meaning that an exemplar’s essence determines one and only one category membership, which implies that essentialised categories have impermeable boundaries; homogeneity, that is, the members of a species or life form are homogeneous in their relevant outfit, even though non-essential variation is allowed for; and stability, which means that category membership will not change over the course of the individual’s lifetime and be transmitted to their offspring. Even young children expect the offspring of a cat to be kittens and not pups (e.g. Ahn et al., 2001; Gelman, 2003; Gelman et al., 2007; Gelman & Hirschfeld, 1999; Keil, 1992; Kronberger & Wagner, 2007; Rhodes & Gelman, 2009). Essentialist cognition has a long history and even though modern education will impart knowledge about genetics (Dar-Nimrod & Heine, 2011; Keller, 2005), essentialism remains a useful figure in discourse.

In the social domain it is important to distinguish between groups where membership is forced, and where individuals have a choice of being part of a group or not (Demoulin et al., 2006; Wagner et al., 2009). Examples for ‘forced’ group memberships are geographic origin, ethnic belonging, and mother tongue among others, which are imposed upon individuals at birth. Then, there are groups like professional associations, religious affiliations to a certain degree, and clubs of hobby enthusiasts, among many others. These two types of social groups differ significantly in the way their members are perceived: Members of forced social groups such as ethnicities, races, and the two sexes are perceived as high on natural kind-ness, while groups with chosen membership are perceived as more entitative than others (Haslam et al., 2000, p. 121). This finding illustrates the basic message that Rothbart and Taylor (1992) have formulated earlier: Forced social groups seem to be spontaneously perceived as natural kinds.

The oft cited study by Haslam and colleagues (Haslam et al., 2000) ² did not assess essentialist ideas about social groups directly, but had respondents judge a number of groups with regard to their perceived discreteness, naturalness, immutability, historical stability, etc. The social groups were called generically as ‘Asians' versus ‘Hispanics', as ‘black people’ versus ‘white people’, ‘Catholics' versus ‘Jews' etc. Respondents were presented with semantically laden labels that addressed the local social representation of the groups. Hence, revealing essence-related semantics carried by the group representations is one thing, but the other issue is to unravel the mechanism that justifies essentialist cognition.

There are virtually no studies showing the mechanisms involved in essentialist cognition, that is, which marker attributes respondents would use to intuit an individual’s essence marking a real-life person’s group belonging. This latter scenario would be analog to the oft conjured ‘tiger example’ used in literature to exemplify the concept of essence (e.g. by Ahn et al., 2001, p. 59ff; Gelman & Bloom, 2007, p. 179; Keil, 1992). Imagine seeing a large animal with striped fur and large fangs that growls frighteningly. It entices the observer to imagine a tiger-essence and to place it mentally into the fitting biological category. Having done that, the observer may draw on the inference potential of the animal’s essence and remember that they live in the East-Indian jungles, are dangerous, and feed on animals, for example.

The latter example highlights a problem that has to my knowledge not been addressed in psychological research: Which specific attributes of exemplars carry the inference potential regarding social group membership and how does an essentialist judgement come about? If individual members of natural or social categories can be recognized as belonging to a specific group, then they must share a sum of attributes with other conspecifics that is clearly discernible; there must be one or several diacritical markers. Without distinctive characteristics, the intuition of an essentialist inference does not work. In the case of animals it is easy to perceive individuals as birds with feathers, tigers with a striped fur, and wasps as flying insects with a sting.

In social life, the problem of discovering diacritical markers of individuals is a bit more problematic than in the natural domain. If we imagine persons walking in the street, there will rarely be the possibility to recognise a single distinctive characteristic of others that would allow to infer their group membership. In their majority individuals in modern societies rarely follow a clear dress code besides fashion. Exceptions are conspicuous attire that some groups of Rom, orthodox Jews, or traditional Indians prefer, or body pigmentation that may give rise to assumptions about an individual’s racial or geographic descent. Particularly in the case of chosen group belongings, markers that allow to infer a person’s belonging are much more subtle even though some social groups tend to advertise their ‘colours'. To infer whether a passer-by can be assigned to the group of medical doctors, stamp collectors, or to a political party, the perceiver needs to engage in communication with the target. Only a close encounter or a direct question can reveal the social and political values that legitimately characterise a medical doctor, hobbyist, or a political party member.

There is a catch though: Typical characteristics of members of forced groups may not immediately be easier to recognise than those with chosen group memberships. Where the two categories of groups differ, is their fulfilling an essence’s criterion of historical continuity. Members of forced ethnic or language groups are likely to remain affiliated to their parents' group from birth through their life. This is not to deny that individuals with an imposed group belonging may change and join another affiliation, but they will barely be able to shed their mental and social habitus or the excellent command of their mother tongue. In contrast, membership in chosen professional, hobby groups, or others are not immutable, not discrete, they are permeable, and they are not stable across time. In other words, chosen group membership does not conform to the constitutive definition of essentialism. This the reason why it barely makes sense to apply the term essence.

Another important element with essentialism is whether the members of a group project essentialist ideas onto members of an outgroup in an act of stereotyping (e.g. Haslam et al., 2002; Yzerbyt & Rocher, 2002) or whether they are interested in essentialising their own group and group identity in order to preserve it as known from minorities who may be interested in promoting their groupness (Bastian & Haslam, 2008; Morton & Postmes, 2009; Wagner et al., 2017). It has been shown, for example, that ethnic minority group members tend to increase their self-essentialisation when presented positive group feedback and to reduce it with negative feedback (Zeromskyte & Wagner, 2019). Also, ingroup identification correlates positively with perceived ingroup entitativity, which members can see as a resource for personal needs (Yzerbyt et al., 2000).

These findings point to the important role that identity and ingroup formation play in balancing the intuition of a stable group essence even though it has barely been addressed. The present paper posits that forced groups such as ethnies, their group organization, and ethnic identity provide a route to understanding where social essentialism comes from. These are issues that psychology is not well-equipped to consider. Ethnic groups define their boundaries and encourage replication of their norms and markers in order to persist over time. Their frequent endogamy can be conceived as a ‘functional homology’ with natural species, which provides a psychologically justified ‘natural’ foundation of ethnic identity and strengthens conformity, groupness, and self-essentialisation. Ethnic identity is transmitted between generations by bio-social processes that govern enculturation and language attainment. Bio-social processes of enculturation, indeed, inseparably merge genetic aspects and social upbringing.

Cultural niche, identity, and essentialism

The cultural niche

Recent approaches in the Extended Evolutionary Synthesis (Müller, 2017), among other aspects, include an organism’s activity in addition to the passive environmental selection pressures that tend to increase the frequency of beneficial alleles in the population of a species. Beneficial alleles are those that, together with all other genetic provisions increase the biological fitness—that is the long-term reproductive success—of an individual’s genome such that the respective trait may eventually become dominant in the species' population. The sum of all natural selection pressures to which a population is exposed is called the population’s niche. Environmental conditions though, are not stable relative to an organisms' behaviours. That is, organismic behaviour can change the organism’s niche for example by movements, for example, by drifting towards a shadowy place, by preferably staying in a protective environment, by building a nest, or by migration. The behaviour that leads to the choice of a beneficial environment will entail a fitness advantage. Hence, one can say that organisms engage in niche construction, which is selective because the organism’s metabolism and activity contributes an evolutionary pressure on the genotype, and it is constructive because it is a consequence of an organismic behaviour (Laland et al., 2015).

From this perspective the co-evolution of genes and cultural characteristics as well as the active search for, or shaping of niches by organisms implies “that niche-constructing organisms can no longer be treated as mere ‘vehicles' of their genes because they also modify selection pressures in their own and in other species’ environments, and in the process, they can introduce feedback [to their genome]” (Odling-Smee et al., 2003, p. 240). It is clear hence, that human culture with its institutions, traits, and habits are a massive form of niche construction found with the human species where culture modifies the selection pressures exerted on the genetic outfit (Kendal et al., 2011; Laland et al., 2001).

The effects of gene-culture interaction are well illustrated by the evolution of lactose tolerance within pastoralist populations, who used their life stock’s milk for consumption. The process of allele selection that allowed humans to digest milk after weaning transpired in about 7000 years after the beginning of domestication (Bersaglieri et al., 2004). The potential ability to use milk in one’s diet, hence, was a strong positive selection pressure where a cultural behaviour—cattle breeding—increased the frequency of the respective allele in the population, which in turn raised evolutionary fitness.

There are several other examples of gene-culture co-evolution of which the evolution of ingroup cooperation and outgroup rejection is particularly interesting for social sciences. It has been supposed that certain genes correlate with ingroup cooperation (Henrich, 2004; Sabeti et al., 2007), altruism beyond helping one’s next of kin (Fehr & Fischbacher, 2003; Richerson et al., 2016), the development of norms in groups by social learning (Gintis, 2004; McElreath et al., 2003; Moya & Henrich, 2016), the tendency to punish deviating group members (Boyd et al., 2003), the ability of mindreading (Whiten & Erdal, 2012), and the capacity to anticipate behaviour implied by an individual’s social position (Hirschfeld, 2013).

It is theorized that sexual selection may play a significant role leading to gene-culture co-evolution is. Even though some sexual preferences may be social and transient, “…culturally generated sexual selection was found to be faster and more potent than its gene-based counterpart. Given the pervasiveness of cultural influences on human mating preferences, social transmission may exert a powerful influence on the selection of secondary sexual characteristics and other physical and personality traits that affect human mate choice” (Laland et al., 2010, p. 141). Sexual selection significantly accelerates the promotion of alleles related to culturally significant phenotypic traits and attributes (Ihara et al., 2003).

Ethnic identities

Cultural niche construction creates selection pressures that contribute to the evolution of group and intergroup-related behaviours. Rudimentary forms of social and intergroup behaviours can also be observed with many primates (Kappeler & van Schaik, 2002; Lindenfors, 2018) primarily with chimpanzees (pan troglodytes) and bonobos (pan paniscus). In the latter species a multi-level society-like organisation is relatively frequent (Grueter et al., 2012) and intergroup relations can take many forms, ranging from peaceful to lethal, depending on the resources that are at stake (Mitani, 2023; see special issue introduced by Van Belle et al., 2020). In the human case, group level-oriented behaviours comprise establishing and maintaining group identities, such as mastering explicit and implicit social norms (McElreath et al., 2003), norm-conformity (Muthukrishna et al., 2016), and to generally favour ingroup members in an intergroup context (Fu et al., 2012).

A group’s identity is shaped by local subsistence arrangements, which influence specific belief systems, rules, norms, patterns of social exchange, marriage arrangements, and rules of legitimate descent. A particularly relevant part in ethnic identities is a wide variety of visual and acoustic markers that allow to distinguish members from non-members. These include attire, language and dialects, and special body features like cranial deformation, scarification, and tattooing, which carry symbolic meaning and are frequently a source of pride. Ethnic markers allow to recognize individuals sharing similar norms and who may be more likely to engage in cooperation. Visual body markers may function as a ‘burn mark’ of, for example, cattle. It is the ultimate marker of group belonging, and it largely impedes an individual’s option to shed their affiliation when stepping outside of the ingroup. This complex of identity-related attributes, behaviours, and ways of thinking is affectively charged and constitute the group’s cultural micro-niche (e.g. Alberts, 2008; Fuentes, 2015; Whiten & Erdal, 2012).

A cultural micro-niche is likely to exist for substantial periods of human pre-history, because it is adaptive and beneficial enough to allow the group’s survival. This is the reason why a child’s mother and kin in traditional societies focus on the identity-related behavioural norms and diacritical markers to secure the child’s successful integration in the community. Part of the integration process are initiation rituals and rites of passage that punctuate the life course, marking transition from childhood to adulthood and responsibilities (Forth, 2018; Van Gennep, 1909). Traditional groups, hence, tend to broadcast the conspicuous diacritical features that mark the group’s identity.

Ethnic identity can take different forms, but it will always be relational. It is relational in the sense that a group needs a name and defining characteristics distinguishing itself from others. Identities can be relatively stable as a set of markers and characteristics, it may be predominantly defined by kinship (e.g. Keyes, 1981), or by the primary activity providing the group’s livelihood (e.g. Astuti, 1995). As a matter of course, ethnic groups may not be highly homogeneous among their members. Homogeneity is only required with regard to a certain extent of adherence to the rules, norms, loyalty, which together constitute commitment (Boyd & Richerson, 2001).

Animal species, ethnic endogamy, and essentialism

Biological species are defined as groups of “interbreeding natural populations which are reproductively isolated from other such groups” (Mayr, 1963). In a time perspective, a species is a “single lineage of ancestor-descendant populations which maintains its identity from other such lineages, and which has its own evolutionary tendencies and historical fate” (Harrison, 2013; Wiley, 1978). In biparental species descent is defined by within-species recognition of conspecific mating partners which share a common fertilization system and physiological barriers against procreation with non-specific individuals (Paterson, 1985). That is, individual animals must first recognise potential mating partners that are likely to co-produce viable offspring, and second, these features need to be conspicuous enough to avoid any investment in ‘wrong’ partners. The central aspect of a species is a formation of individuals that exist across time and maintain geneflow among themselves, but not with individuals from other lineages. Intraspecific exclusivity avoids investments in procreation that may not result in viable offspring.

Ethnic groups show a significantly similar behaviour pattern. Stone age foragers growing from kinship groups to ethnic groups must have undergone a culture-gene coevolution that generalised genetic kinship onto membership in their jointly foraging group, marking group belonging to enhance cooperative behaviour and sharing of resources (Ihara, 2011). This does not mean that ethnic groups are extended families or clans. They just needed to develop a sufficient level of cooperation and helping behaviour that can be based on imagining kinship instead of a real genetic lineage, and the imagination of kinship is facilitated by an ideology of descent and the rule of endogamy. Note that rules of endogamy primarily apply to marriage and not to sex per se (Boyer, 2018, p. 256).

Ethnic groups tend to endorse a norm of endogamy that is in part driven by parental enforcement (e.g. Apostolou, 2007; Apostolou, 2010). Endogamy may also be driven by the fact that culture is acquired at an infant age and mostly stable during ontogeny, such that adolescents are likely to find partners stemming from co-ethnic parents, thereby continuing the norm. Hence, hopeful mating partners practising the group’s norm of endogamy would tend to “create the illusion that their cultural mastery [of endogamy] was biologically inherited”. To facilitate this process, “incipient groups began labelling and conspicuously marking themselves with cultural ‘phenotypes' to improve the accuracy of the interactional discriminations” (Gil-White, 2001, p. 532). Endogamy is beneficial because it helps maintaining an ethnic group homogeneous and avoids miscoordination with regard to the rules, norms, and interactional expectations that cross-ethnic relationships are likely to entail (Fuller & Narasimhan, 2008; Kalmijn, 1998; McElreath et al., 2003; Nave, 2000).

There is a remarkable parallelism between the procreational organisation of the most conspicuous mammals and the respective organisation of ethnic groups. Given this, ancient humans, being socially and politically as intelligent as modern mankind (c.f. Graeber & Wengrow, 2021), certainly have understood the functional similarity of a species' inter-generational stability in the animal domain and ethnic stability across generations in the social domain well enough to see this mapping as connoting more than a coincidence. The reasoning that matches functionally similar processes in different domains establishes a ‘functional homology'. ³ In the present case, the term ‘homology’ is used to characterise the relationship between the function of a species as a procreative unit with information pathways such as signals, cues, and receiver mechanisms to recognise valid mates, and the respective diacritical marker system in the identity sphere of an ethnic group. Both phenomena emulate the same principle of sustaining a group formation, albeit with different means. Intraspecific recognition and intra-ethnic identity do share a common antecedent and relate to each other by their functional similarity.

As shown in section 2, people tend to assume that the stability of animal species across generations is a consequence of an essence inherent to the members of a species and passed on between generations (e.g. Atran et al., 1997). Consequently, the conclusion establishing the functional equivalence between species and ethnic groups also projects the framework of essentialist thinking to co-ethnic generations. In both, the animal and the ethnic case, the fictive essence guarantees that exemplars of subsequent generations can be expected to belong to the same group.

The functional homology between natural and social processes, effectively, naturalises an essentialist cognition. This conclusion can be called ‘deep essentialism’ because it furnishes its social target with a hardly mutable natural reality in a person’s imagination. Rendering a group’s identity as natural, justifies its existence and makes it a lasting feature across generations. Perhaps the widespread belief in totemism that postulates relations of animal and plant species with individuals or groups is a faint echo of this functional homology. The primordial invention of deep essentialism applied to group identity can be regarded a crucial step in human development and a huge cognitive, political, and social achievement in constructing the cultural niche for millennia to come.

So, what is the form of people's representation of an essentialised and naturalised social category? Are they aware of their group's homology with animal species? Of course, cognizant people do not replace the image of a social group and its members with the image of a herd of animals in their mind. The representation of a naturalised group is certainly subtle and probably not located at the explicit cognitive and conscious level but must be seen as an affective and emotional allusion of a ‘bond of togetherness'. An essentialist attribution is a matter of ‘feeling' the group to be more stable and coherent than an arbitrary ensemble of individuals and not as short-lived as a bunch of people waiting for a bus and as decomposable as an artifact. It can virtually be felt like a ‘physical reality'. (cf. Gil-White, 2001; Rothbart & Taylor, 1992; Wagner et al., 2009).

Parenting, transmission coupling, and deep essentialism

Early age parenting and cultural learning

The human brain’s development is genetically driven during the first two-thirds of gestation (Bakken et al., 2016). In the remaining third and in the first few postnatal month’s environmental influences take over in shaping the structure and interconnectedness of the brain (e.g. Pletikos et al., 2014; Raznahan et al., 2012; Trevathan, 2011). Adverse or missing environmental stimulation during this period is likely to result in mental and neurological defects (Jamuar et al., 2014; Silbereis et al., 2016; Vasung et al., 2019).

Postnatal stimulation and physical proximity of the mother, nursemaid, or next of kin (Storey & Ziegler, 2016) activates prewired preferences for face patterns and motion (Buiatti et al., 2019; Lemche, 2003). New-borns with a family burden of autism, for example, do not show face and biological motion preferences (Di Giorgio et al., 2016). Parental behaviour and attention in this early period are also responsible for filial imprinting of attachment security that plays out in later life (Atkinson et al., 2000). Cultural variation of parental caretaking patterns significantly predicts infantile attachment, pointing to a cognitive-representational nature of attachment relations (Lemche, 2020, p. 129). Touch, parent-baby reciprocity, as well as synchronicity of interactions is related to genetic oxytocin pathways of social behaviour (Feldman et al., 2016).

The series of studies within the ‘Bucharest Early Intervention Project’ have provided strong evidence of the importance of early parental contact and care for cognitive and social development. Children from orphanages who were adopted by foster parents up to the age of 24 months of age had the best chances of partially recovering their cognitive deficits (e.g. Nelson et al., 2007). Even more drastic effects of institutionalisation were shown in the barely imaginable ‘experiment’ by the king of the house of Staufers, Friedrich II. In one version of the story he left some new-borns in isolation, only taken care of by wet nurses who were not allowed to talk or otherwise interact with them. The outcome was that all babies died after a few weeks (Salimbene, no year).

Of course, parental care is not a human invention but exists in many vertebrates and all mammals (cf. Kölliker et al., 2012). It is an evolutionary niche involving two parts. Besides providing food, the parent's part consists in stimulating the baby in as many communication channels as possible (Feldman & Bakermans-Kranenburg, 2017; Hertenstein, 2002). Secondly, the baby's innate part consists in eliciting and responding to attention by reacting to eye-mouth triangles as proxies for faces. The baby's tools for establishing a connection with parents are the baby's cuteness schema (Kindchenschema) to elicit a caring response and supportive acoustic signalling. As an evolutionary niche, parenting at least up to the age of a child's acquisition of language has a genetic component and is not arbitrary (cf. Geary & Flinn, 2001; Uomini et al., 2020). “Members of both generations must act to realize their investment as parents or inheritances as offspring. The niche is thus a way of life…” (Stotz, 2017, p. 5). Any failure in the interaction between parents and offspring from the late prenatal to early postnatal stage will diminish the individual wellbeing and overall fitness of parents and offspring (Narvaez et al., 2014). The strong and lasting effect of early age imprinting has not gone unnoticed by founders of religions who insist on imprinting descendants of their followers at the earliest age possible.

This primordial building stone of the human cultural niche guarantees the basic enculturation of the young members of a culture, the acquisition of the local language, and the incorporation of cultural practices, tastes, and cognitive dispositions. The processes, their structure, and the coordination and synchronicity of the behaviours of the participants in early age, that is the new-born and their mother and kin, is universal with some cultural variation (Lemche, 2020), but the domains that exhibit such critical periods, the effects of any variation as well as the hormonal pathways need further investigation (Feldman & Bakermans-Kranenburg, 2017). Early age parenting is driven by genetic determinants that govern the new-born’s as well as mother’s behaviour and the extended family’s attention towards the baby and therefore is a naturally co-determined process with little flexibility (Sear & Mace, 2008). The biological importance of parenting and care does not contradict the fact that in situations of hardship and scarce resources, parents may decide to abandon new-borns (e.g. Hausfater & Blaffer Hrdy, 1984).

The prolonged human developmental span is an evolutionary response to the fact that human groups differentiated and created cultural spaces with increasingly complex patterns of social organisation. Complex cultures require ever more flexible mechanisms of learning that allow young members of a cultural group to adapt to the requirements of group life. This consists of an inclination for cooperative behaviour, sharing of resources, social intelligence, a relatively well-developed capacity for language use and cultural learning, and a degree of political empathy for the desires of others (Deffner & McElreath, 2020; Tomasello, 2020). Cultural learning mechanisms are not comparable to what children and adolescents in modern societies experience as school and academic teaching and learning. They are much more tacit and happen in passing as well as in playful interactions like the children's attainment of language during the linguistic window of opportunity. It is a genetically driven openness to attend to, and to imitate linguistic sounds, cultural rules, and associated behaviours (c.f. Heyes, 2016).

Psychologists tend to refer to the process of early and extended parenting that imbues the offspring with a cultural identity as ‘upbringing’ and ‘social background’, which are understood as socially constructed (e.g. Rangel & Keller, 2011). Looking at these processes in detail, however, reveals that evolution has created a set of intermeshing learning opportunities on the side of the new-born and infant, and on the side of the mother and close persons (feeding, cuddling, communicating etc.), that are as biologically necessary as they appear to be social and intentional.

Enculturation as an evolutionary provision

Cultural groups have existed, prevailed, migrated, and split for tens of millennia. It does not come as a surprise that during this time span groups have undergone selection processes, which withered out groups that were less successful than others in competing for resources and in maintaining a thriving ethnic group life. Cultural Group Selection does not directly follow Darwinian principles of phenotype and genotype selection driven by the stochastics of biological fitness, but by shaping the biosocial conditions that allowed early-age parenting and cultural learning processes to become effective mechanisms in trans-generational continuity (Boyd & Richerson, 2010; Henrich & McElreath, 2003; Richerson et al., 2016). On one hand the developmental conditions of a group’s offspring must contribute to the individuals' life success in the group they are born into, and on the other hand the group must be preserved as a niche that successfully holds its ground relative to competitors.

Individuals will be well adapted to living in their ethnic group, if they conformed to the pattern of ethnic norms. Non-conformism entails ostracism and a lower rate of fitness (Hawkley & Capitanio, 2015; Muthukrishna et al., 2016). As conformism is beneficial for an individual’s progress in life, it is also beneficial for the group and an evolutionary advantage as far as it helps avoid ingroup strife (Denton et al., 2020; Morgan & Laland, 2012). Cultural learners will actively search for valid sources of ethnic knowledge (Heyes, 2016; Moya & Henrich, 2016). Generic group-related language use by parents and co-ethnics such as “We are X, and X are such and such”, as well as anecdotes and narratives consolidate essentialised beliefs about the referenced category X to be of a kind (Birnbaum et al., 2010; Kashima et al., 2010; Segall et al., 2015). Language use can be assumed to be of primary importance in children and adults' understanding of a social category’s essentialised kind-ness even if experiments have rarely been conducted with ethnic samples (e.g. Cella et al., 2022) (Gelman & Heyman, 1999) (Gelman & Roberts, 2017; Noyes & Keil, 2019; Vasilyeva & Lombrozo, 2020). Hence, intergroup “variation is transmitted to new generations by the human capacity to acquire norms and social institutions [, which…] include mechanisms of selective punishment, reward that reduce small-scale variation in behavior, and not least language. Human organizations compete, often in highly organized ways, and the success and failure of groups in such competitions is often determined by institutional and other cultural differences.” (Richerson et al., 2016, p. 16)

In summary, the comprehensive system of the bio-social institutions of parenting, imitation, and cultural learning as furnished by evolutionary processes provides an immersive milieu that tacitly conveys the intuition of a naturally given ethnic identity across generations. The intuitive feeling of cognizing a natural group essence can be transmitted as a bye-product by the cultural institutions making up the enculturation process without the need to postulate innate pathways.

Entailments of deep essentialism: adoption and social mobility

It was argued that a belief in deep essentialism imparts stability to a group by naturalising ethnic identity. Indeed, what can be claimed as more stable than an identity imagined as a natural given? If the members of a tribe imagine themselves to be as naturally organised as the leopards in their surroundings, this suggests the tacit conclusion that the group’s offspring will share their tribal identity as naturally as the kittens of leopards will be leopards later in life. Most factors found in research on Cultural Group Selection relate to the stability and coherence of ethnic groups, such as a tendency of conformism, ingroup favouritism, the endorsement of norms and markers, and others. These factors contribute to perpetuating cultural continuity by providing a coupling mechanism between generations (Boyd & Richerson, 2010), which gives the group historical continuity (c.f. Smeekes & Verkuyten, 2015). Each of these factors is related to normative conclusions: Deep essentialism justifies enforcing conformism and punishing ‘unnatural’ deviance; if individuals favour the ingroup at the expense of the outgroup, this choice appears as ‘natural’; and if norms and markers are naturally given, their observance is equally ‘natural'.

Early age parenting and cultural learning are the objective side of the transmission and perpetuation of group identity across generations; they preserve the group’s intangible cultural inheritance, that is the tastes, norms, and beliefs. These objective processes usually happen tacitly, inconspicuously, and mostly escape conscious awareness. The invention of deep essentialism provides the subjective side and social rationalisation for the components of group identity and ways of interaction, because an essentialist cognition is a meta-cognition rendering the elements of identity a natural given. Deep essentialism also answers the question of ‘how is group identity acquired?’ It provides the reason for the group members' ingrained feeling of belonging by postulating an invisible causal agent that is shared among group members. Taken together, deep essentialism serves a purpose by stabilising ethnic identities and by giving a reason for a group’s existence.

If an essentialised identity of the ingroup appears as natural in discourse, so does the different appearance of outgroups. Usually, neighbouring groups and those that maintain relations of economic exchange, are aware of the cultural characteristics, beliefs, and norms of their transaction partners. If the culture of the outgroup is perceived as stable and essentialised as one’s own, this allows to draw inferences about the likely behaviour of their members in encounters (Moya, 2013), which is an important skill in intergroup situations. This is the often cited ‘inference potential’ of essentialised categories, that is the capacity to make an informed guess about the behaviour of members of groups (c.f. Boyer, 2018, p. 256f; Wagner, 2021).

Deep essentialism discourages intergroup mobility (Boyd & Richerson, 2010) and many ethnic groups rule out that children originating from an outgroup can become full members of the ingroup even if adopted at an early age and raised like an ingroup child. In this view, the adopted individual cannot immediately become a full ethnic ingroup member because the adoptee lacks the specific ‘essence’ that is only passed on by endogamic reproduction (Gil-White, 2001). If individuals migrate into the community of another ethnic group, they will be considered member of their original kind until their death. Usually such transitions take a few generations for their offspring to be recognised as co-ethnic (Gil-White, 1999).

The psychology of contemporary societies is not very different from traditional societies and a disguised deep essentialism still rules. In Europe, most ethnic boundaries boiled down to languages and nationalities, and it is relatively frequent to marry into another language or national group (Kalmijn, 1998). Counter examples are small endogamic minorities. In the USA, the multitude of migrant nationalities under one state’s flag led to weaker ethnic boundaries and with it to a relative disregard of traditional rules of descent. But the catch is that, while national identities of the early European immigrants wither, they are replaced by the overarching reference to their families' European origin. European descent becomes the new reference that motivates boundary making towards Latin, Asian, or African Americans (Qian & Lichter, 2007), thereby introducing a tacit rule of pigmentation-related endogamy preventing ‘miscegenation’ (Holtz & Wagner, 2009; Houseworth, 2011; Wagner et al., 2010). Similar processes unfold in the case of immigration (Chao & Kung, 2015; Moftizadeh et al., 2021; Smeekes & Verkuyten, 2015). That pigmentation becomes the diacritical feature distinguishing regional, or race groups is no coincidence because it is also an attribute that is naturally imposed upon individuals and therefore a target for essentialisation. This is the place where deep essentialism and its naturalising entailment sneaks into contemporary societies.

Another instance of ‘intergroup encounter' is intergenerational upward mobility. When an individual from a ‘lower' social class rises to a ‘higher' class through education, for example, they frequently report the feeling of a ‘split' personal identity and associated habitus (Naudet, 2018). Many social climbers cannot help the feeling of not ‘really' belonging to the higher class because of their former, affectively, and essence-laden identity. This split reflects a degree of incompatibility between the essentialised habitus they were raised in, and the display demanded in their professional milieu. This phenomenon is also a prime example of the affective component imprinted in group identities (Friedman, 2016; Mallman, 2017). Socially mobile interviewees talk about “vast distances, or ‘chasms’, between certain socio-economic groups, […] with the suggestion that their members are therefore significantly or even inherently different kinds of people; […with] specific class-based outlooks, mindsets and feelings […].” (Carter, 2024, p. 182f) Of course, people with different ethnic and social class background have always mixed and mingled and unavoidably brought with them the incorporated affective side of the group identities they were raised in.

Conclusions

The present theory suggests that group-related essentialism has a natural origin in its role for identity construction in ethnic groups. Ethnic identities comprise artifacts as well as norms, interaction patterns, forms of social exchange, beliefs, and rules of endogamy, depending on the ways the people procure their livelihood. Early humans cannot have missed the functional homology between their own endogamic social organisation and natural species. This insight suggests imagining their group’s identity also as a natural given. The customary ways of early age parenting, enculturation, and language acquisition ensured that the group’s identity, held together by the meta-cognitive ‘essentialist bond’, was being transmitted across generations. Working on the level of feeling, affect, and body knowledge, these bio-social processes also transmit the norms of conformism, ingroup preference, and the idea of cultural boundaries. Local cultures and ethnic groups, hence, form relatively delimited micro-niches of survival within the large-scale process of evolutionary human niche construction. The role of essentialised ethnic identity is nowadays played by race and geographic extraction because both characteristics are forced upon humans like ethnic belonging in the past.

Social essentialism that originates in the animal domain shares the principal characteristics with its natural source: The essence of members of an ethnic group is perceived as immutable because deviance is punished, it is discrete, because it is specific for one ethnic kind, it assures that an essentialised group is largely homogeneous as far as the relevant markers are concerned, and an essentialized identity is cross-generationally stable by enculturation. This is due to the power of essentialised identity rendering a group as a kind and it means that self-essentialised group identity is logically prior to outgroup essentialisation.

Taken together, the theory argues that perceiving a group can sensibly only be considered essentialist, if at least the aforementioned defining elements apply. In this case any attribution of essence to a group explicitly or implicitly naturalises the target. Any representation of a group that falls short of this definition may be a case of the inherence heuristic (Cimpian & Salomon, 2014), but not essentialism in its fundamental understanding.

The foregoing sections have presented evidence that children’s upbringing consists of early age parenting and children’s cultural learning that is well capable to provide a mechanism of transmitting the intuition of group essentialism across generations without being innate. In this case it may well be that the crucial bio-social mechanisms of enculturation underlie an evolutionary Darwinian selection instead of the essentialist cognition itself.