I regard all native Peruvian civilization as a unit – a larger historical whole, a major areal culture with time depth [1].

In Europe and the People without History, Eric R. Wolf [2] stated that “we all inhabit one world” and although terminologies such as “nation,” “society” and “culture” may give us an impression that there are fixed boundaries that divide us, communities, in the present as well as in the past, coexist and coexisted establishing a complex network of interaction. Likewise, Barth [3] asserted that there is mobility, contact, and flow of information across boundaries and that “ethnic distinctions do not depend on an absence of social interaction and acceptance.” Furthermore, in his classic work about the hillside Kachin, Leach [4] pointed out that interaction has the potential to introduce change; in particular, Leach argued that interaction allows some members of society to enhance their prestige by accessing not only foreign goods, but also foreign spouses. Thus, in the name of prestige, for example, human societies often invest considerable effort in establishing and maintaining interaction with higher rank societies from far away.

Archaeological research has consistently shown that human societies rarely, if ever, remained isolated one from another. Within archaeology, there has been a growing awareness that human societies invest energy to be part of larger sphere of interaction and that the relationship has the capacity to shape and reshape on an ongoing basis the societies in contact [5-11]. Indeed, the network of interaction established by each society enables the transfer not only of material goods, but also of ideas, knowledge, technologies [12] and even diseases [6]. The transfer and subsequent spread of the above carry the potential that recipient cultures can use them rather differently, ultimately provoking change in a particular society that otherwise, perhaps, would not have occurred [13].

Central Andean archaeology has provided examples of cultural interaction. Indeed, Kroeber [1] was among the first to regard “all native Peruvian civilization as a unit – a larger historical whole, a major areal culture with time depth.” Only four years later, this same view was fully endorsed by Bennett, Bennett and Bird [14,15]. The concept of “horizons,” initially discussed by Willey [16], and followed by subsequent researchers [17], were the outcome of inter-societal contact that resulted in the widespread “recurrence of specific features of style” Willey [16] as well as of other cultural practices shared over a large territory, such as coca chewing [14]. The principal importance of these studies, and of those that followed [18-20], was the realization of the existence of cultural relationships among the various cultures of the Central Andes that allowed the dispersal of various cultural practices that included the making and consumption of freeze-dried meat named charki, fermented beverages commonly named chicha, and the practice of coca chewing. Charki, chicha and coca chewing are unique features that define the cultures of the Central Andes. According to William Duncan Strong [19], the idea of interconnectedness among the various cultures of the Central Andes can easily be pushed back to the work of Max Uhle and highlighted that the cultural development of any one region of the Central Andes cannot be fully understood independently of that of adjacent areas.

The aim of this paper is to discuss the interaction between the Huarpa culture of the Peruvian central highland valley of Ayacucho and the Nasca culture of the Peruvian south coast region. Shortly after a visit to the urban center of Huari in the Ayacucho Valley [18] observed “similarities” between the ceramic styles of the Huarpa and the Nasca that flourished during the so-called Early Intermediate Period (ca. AD 1–550). Subsequent researchers acknowledged the existence of stylistic parallels between these two cultures and have identified the “Nasca influence” [21,22]. I argue that the Nasca influence, although frequently mentioned by specialists working in the Ayacucho Valley, has not been fully discussed; existing arguments only point out to the most obvious outcome of the interaction, such is the stylistic similarities between Nasca and Huarpa ceramics. As further discussed below, the “Nasca influence” was more than just the modifications readily noticeable in the late Early Intermediate Period ceramics of the Ayacucho Valley. More recent research indicates that the highland valley was at the receptive end of this interaction, not only accepting and incorporating Nasca ceramic traits, but also ideas and cultural practices that ultimately resulted in the unprecedented transformation of the region into a state level society.

In the distant past, the interconnectedness between the inhabitants of distant places probably occurred due to various reasons. The desire to gain access to locally non-available resources by means of barter [23] or by establishing direct control over land located at different ecological zones must have been instances that enabled the interaction between unfamiliar peoples from far away territories. Prestigious centers must have also functioned as magnets attracting visitors and/or pilgrims from different regions and thus allowing contact among travelers coming from several directions. Finally, “prestige, curiosity, a spirit of adventure” [24] and the human impulse of exploring the unknown likely played a key role in the establishment of interconnected communities across large territories.

Following the initial call made by Wolf [2] who asserted that “human populations construct their cultures in interaction with one another and not in isolation,” there has been renewed interest in the study of cultural contact, including in the manner such interaction induces change. Indeed, researchers have shown that cultures have been interconnected economically and politically at both elite and non-elite levels. At some time, and between specific cultures and regions, such interaction may have also been more intensified than in other regions. Therefore, there is a general consensus that the cultural development of any region cannot be understood separately of that of adjacent regions.

The outcome of interaction between geographically, ethnically, and linguistically distant people is the dispersal of goods, customs and ideas over large territories [12]. Because peoples interact with members of countless distant communities and such process takes place at various locations and at different times, it is conceivable the further spreading of the goods, customs and ideas transferred. Furthermore, and during the same process, the interacting groups likely passed and learned other concepts that, perhaps, was not necessarily intended for sharing. Thus, interaction probably facilitated the dispersal not only of the intended material items, but also of other unintended goods and customs. Then the eventual acceptance of foreign goods, customs and ideas, intended or not, in turn, carry the potential of modifying the existing way of life of the cultures in contact [25]. Indeed, Lamberg-Karlovsky [7] makes an interesting case, where there is the possibility that the borrowed ideas may not necessarily be used in the same manner as it was at the original setting, but may be modified by recipient societies, thus bringing about change.

The region is recognized as having “one of the most difficult and demanding landscapes in the world” [26], with the capacity of even isolating communities and entire regions (Figure 1). However, the otherwise formidable barriers imposed by nature were turned to advantage by “developing a productive system that incorporated and used the maximum number possible of different resource areas” [27]. In this manner, the most difficult and demanding landscapes was seen as ecological diversity [28] that would be exploited in a productive manner by maintaining simultaneous control of various ecological niches [29]. By developing strategies such as this, Andean societies gained self-sufficiency [30] and simultaneously established networks that linked countless communities.

Figure 1: A view of the Central Andean landscape.

the roads and trails (Figure 2) that traverse the rugged central Andean terrain [31] and suspension bridges (Figure 3) ingenuously established over deep canyons and torrential rivers [17,32] were built with the main purpose of reaching out unknown territories and in this manner tying previously isolated distant communities. Because the establishment of roads and bridges demands time and energy and in order to be useful, they need to be maintained and renewed periodically it is apparent that such an investment of time and human energy – let alone the actual distances walked – is a strong testimony to how important it must have been to be in contact with peoples from remote territories (Figure 4). Likewise, the presence of roads and bridges across the difficult central Andean landscape highlights to how critical it must have been to establish access to distant lands. Therefore, there can be little doubt that this effort implies not only the active and purposeful engagement of communities in the process of interaction, but also demonstrates that contact between the inhabitants of far-away territories was central to the wellbeing of past Andean societies [30]. From this brief overview, there is an economic component acting as the main engine that urged peoples from remote regions to uphold reciprocal relationships.

Figure 2: Trails criss-crossing the Central Andean landscape.

Figure 3: Tinkuychaka, a suspension bridge over the Pampas River, Central Peru.

Figure 4: Llama caravans in Central Peru.

When the pottery of two regions displays such similarity, it suggests that their societies were actively involved with each other [33].

It has long being recognized that the Nasca culture [34] of the Peruvian south coast region exercised strong influence over its highland neighbour, the Huarpa culture of the Ayacucho Valley [21,22]. Early in the history of archaeological studies in the Ayacucho Valley, researchers observed the occurrence of late Nasca ceramic designs depicted on the Ayacucho Valley ceramics [18,21,22]. In addition, the Ayacucho Valley ceramics had incorporated several Nasca ceramic traits that included the use various colors that until then were known only to the Nasca, as well as surface polishing of the vessels. The new vessel shapes began to resemble late Nasca vessel forms [21,22,35,36]. As the Early Intermediate Period came to an end, the Nasca influence in the Ayacucho Valley rather intensified as manifested in the emergence of a new ceramic style – the Cruz Pata style – that exhibits more technological sophistication and depicts Nasca phase 7 designs [21,22,37,38].

A fundamental question that deserves serious consideration is with regards to the circumstances under which the Nasca influence occurred. An early attempt to address this issue argued that the Nasca influence probably emerged from the geographical proximity between the two cultures [22]. Following this explanation, both the Nasca and the Huarpa maintained trade relationships. Two cultures occupying two markedly distinct environments (one coastal and the other highland) and therefore with access to different resources likely had much to offer to each other. In addition, there are more opportunities for reciprocal interactions between adjacent societies than with cultures from far away. Therefore, the Nasca influence could have emerged from resource exchange. However, archaeological research on the south coast in particular has produced little evidence that would support the existence of a trade network between the Nasca and the inhabitants of the Ayacucho Valley.

Leaving this unresolved issue for a moment, an important point that deserves to be stressed is that parallel to the appearance of late Nasca designs in Huarpa ceramics there was population increase in the Ayacucho Valley [22]. Until recently, however, it remained unclear how and why such population growth occurred. More recent research on the Peruvian south coast indicates that about the time population increased in the Ayacucho Valley, settlements decreased significantly not only in numbers, but also in size [39]. It is further argued that such a drastic change occurred in the midst of a severe drought that affected the south coast region [39-41]. Although it remains uncertain where exactly the people went, there are suggestions that at least some of them perhaps migrated to the Ayacucho Valley. The population increase noted above may be due to the influx of south coast immigrants to the region. By means of bioarchaeological and biochemical analysis, future researchers may be able to determine whether Nasca immigrants had actually arrived to the Ayacucho Valley.

Following the above possible scenario, it is tempting to suggest that the apparent rapid technological sophistication of the Ayacucho Valley ceramics has something to do with the actual presence of south coast inhabitants in the highland region [36]. As already mentioned, contact, including immigration, facilitates the spread of knowledge and technologies [7,42]. It also is important to point out that the Nasca culture “is internationally renowned for its exceptional polychrome pottery” [43], an advancement of which their neighbours of the Ayacucho Valley probably were aware. When the technology became accessible the inhabitants of the Ayacucho Valley were quick to adopt it. In this context, Middle Horizon Wari ceramics are technologically reminiscent to Nasca ceramics, while different from the local Huarpa ceramics. Thus, taking into consideration the sophistication of Nasca ceramic making technology and the possible presence of the inhabitants of the south coast as immigrants in the highlands, it is feasible to understand the reasons for the rapid innovation of the Ayacucho Valley ceramics. A new, much sophisticated, technology had become available in the region and subsequently adopted.

At the same time, available mortuary evidence in the Ayacucho Valley supports the possibility of Nasca immigrants arriving to the highland region. First, a common Nasca burial position was seated, with the lower limbs flexed toward the chest [44]. Second, for the particular case of the upper Ica Valley of the south coast it has been noted that burials were placed inside stone-lined pits covered by stone slabs [45]. Similar cists and similar body positioning were unknown in the Ayacucho Valley prior to the Nasca influence, but became a common practice with the emergence of the Wari state. The appearance of new mortuary customs leaves open the possibility that peoples of the south coast had indeed arrived to the Ayacucho Valley, especially considering that mortuary practices are idiosyncratic and constitute one of the most conservative institutions.

From the examples provided here, it is becoming apparent that immigration perhaps was the reason for the changes that occurred in the Ayacucho Valley and that the Nasca influence as a whole perhaps deserves to be discussed taking into consideration the issue of migration [46-48]. In addition to reciprocal forms of interaction by means of trade, there are several circumstances that bring peoples from distant regions into contact; to name some, these include drought, invasion, and warfare [9,25,46]. All of the above are capable not only of pushing the inhabitants of certain regions to seek out alternative places to carry on with their lives, but also prompt the transfer of ideas, knowledge and technologies over wider geographical spaces. If the case of Nasca influence in fact represents migration, this at the same time opens the possibility that the south coast inhabitants had previous knowledge of the Ayacucho Valley, with whose inhabitants they perhaps already interacted and thus they followed well-defined routes. The finding of some early Nasca ceramics in the Ayacucho Valley suggests this.

As mentioned at the onset, the existing stylistic similarities between the ceramics manufactured on the south coast and in the Ayacucho Valley late during the Early Intermediate Period represent the most noticeable outcome of the Nasca-Huarpa interaction. Further assessment of available evidence indicates that the picture is more complex and produced profound changes in both regions. In the following section I provide information that demonstrates that following the Nasca influence at least one previously unknown cultural practice was introduced to the Ayacucho Valley [47,48].

About the time the Nasca influenced the highland valley of Ayacucho, on the south coast Nasca artisans manufactured effigy vessels depicting coca chewers as well as individuals carrying coca bags [49-51]. The images (Figures 5 and 6) suggest that the chewing of coca leaves was already known on the south coast by late Nasca times. Previously no such representations were depicted by the Nasca. Comparable evidence does not exist for the Ayacucho Valley.

Figure 5: Late Nasca coca chewer holding coca bag.

Figure 6: Late Nasca coca chewer with bulging cheek.

It must be stressed that coca is an integral part of Andean culture [26,52] and in regions such as the Peruvian central highlands coca continues to play an important role. Until recently, however, it remained unknown when coca use began in the region. Recent archaeological information coming from Convento, a site found immediately north of the Ayacucho Valley, demonstrates the occurrence of coca leaves in a context that corresponds to the time that the Nasca influence in the Ayacucho Valley intensified. The coca leaves were fortuitously found as part of a burial offering and in association with a Cruz Pata style ceramic bottle [53,54]. The coca leaves had been placed between two tupu pins that prevented their deterioration. To the best of my knowledge, this finding represents the earliest direct evidence of the presence of coca leaves for the entire Peruvian central highlands.

The state of preservation of the coca leaves found at Convento is surprisingly good, which makes it possible to readily distinguish it from E. coca Lam. (Huánuco or Bolivian coca), characterized by its much larger and “broadly elliptic in shape, more or less pointed at the apex” [55]. The leaves from Convento are more lanceolate (or narrow abovate) and more or less rounded at the apex, with two well pronounced lines parallel to the midrib. These are some of the salient characteristics of E. novogranatense var. truxillense (Trujillo coca) [55], the coca species adapted to the drier Pacific coast [55,56] and extensively cultivated in the coastal valleys in late pre-Hispanic times [57-59] and more likely also in earlier times [55,60].

The identification of the coca samples from Convento as one type coming from the Pacific coast and the fact that late Nasca artisans represented coca chewers makes it apparent that the concept of using the coca leaves were initially introduced to the Ayacucho Valley from the south coast region about the time the Nasca influence occurred. Before anything else, however, I must point out that preservation of organic remains in regions such as the Ayacucho Valley is poor, thus limiting the recovery of remains such as coca leaves. As a result, it is also challenging to argue definitively that prior to the Nasca influence coca use in the highlands was unknown. Keeping that in mind and taking into account existing tangible evidence, it is plausible to argue that coca was probably brought to the Ayacucho Valley by the Nasca.

Whether coca leaves were intentionally introduced to the highlands or highlanders learned about coca from their south coastal neighbours following the contact between the two regions remains an interesting question, but at the same a difficult one to deal with, at least at the state of our current knowledge. In any case, coca leaves became so integral to the highland populations that, as demonstrated by the Convento finding, even the dead had to have access to the leaves. I must point out that the placement of coca leaves as part of the offering paraphernalia to the dead is unknown for late Nasca burials; hence, this concept appears to have being developed in the central highlands about the time the Nasca influence intensified. By the time the Inka state emerged, coca leaves were regarded as the most sacred of all plants [17,24,61,62] that were given as offering to important landmarks across the empire. More importantly, perhaps, is that with the Inka even the dead carried coca leaves in their mouths [63].

When the Wari state began expanding from its Ayacucho Valley heartland during the Middle Horizon, the south coast was one of the first regions incorporated into the Wari domain [21]. Wari’s early expansion to the south coast may have been facilitated by the already existing links between the two regions, but it cannot be ruled out that the driving force may have been to gain direct access to a region associated with the highly esteemed coca leaves. Moreover, throughout the florescence of the Wari state, the south coast maintained a privileged position [21], again perhaps due to its association with the coca plant.

As for other highland cultures of the Central Andes, including the Inka state, tangible remains of coca leaves are rare. This makes the evidence coming from Convento exceptional. Nevertheless, there are indications that coca was used at the time the Wari state flourished. For example, an offering pit excavated from Pikillaqta, a Wari center in the Cuzco region, uncovered several miniature warriors (Figure 7). One of the interesting features of these figurines is their bulging cheeks [64,65] that is similar to the bulging cheeks of the Inka statue offerings interpreted as being indicative of coca chewing [63]. By comparison, I conclude that the figurines from Pikillaqta represent coca chewing. In addition, there was a Wari coca bag found by Junius Bird at Pacheco, on the south coast of Peru. More importantly, according to Susan Bergh (personal communication) the bag was found containing coca leaves. In this manner, there are indications that coca leaves were used by the Wari state and perhaps it was during this time that the use of this plant became widespread across the Central Andes.

Figure 7: Warrior figurine from Pikillaqta with bulging cheek.

On the basis of indirect evidence, scholars were certain that coca leaves were already used by the time the Wari state emerged. Due to the proximity of the Ayacucho Valley to the eastern lowland rainforest valley of Apurimac, it was suggested that coca consumed by the Wari probably come from that region. In particular, the finding of Wari outposts in the tropical Apurimac Valley strongly supports this possibility. While the Apurimac Valley is well known as a coca producing zone, it is important to consider that the coca cultivated in that valley is the variety with broad elliptic leaf-shape, identified as E. coca Lam. or coca Huánuco [55]. This variety is different from E. novogranatense var. truxillense or Trujillo coca [55], a coca variety with more lanceolate leaf-shape and adapted to the dry Pacific coast. This observation, in conjunction with the fact that late Nasca artisans depicted what appears to be coca chewers, strongly support that the custom of coca chewing came to the Ayacucho Valley from the south coast.

The use of coca leaves on the south coast of Peru in early Nasca times remains unknown. Despite the excellent preservation of organic remains in the region, coca leaves have not been found. By late Nasca, the inhabitants of the south coast had also entered into contact with the Moche of the north coast [37] and it is possible that the Nasca learned about the use of coca leaves from the north coast, a region with a long history of coca use. If the Convento coca leaves originated from the south coast, when did highlanders begin using coca leaves from the eastern lowlands? The presence of Wari outposts in the Apurimac Valley open the possibility that the Wari state perhaps accessed coca leaves from the eastern lowlands as well as from the Pacific coast, in a similar manner to what the Inka State did centuries later [54]. As demonstrated by the findings from Hatunmarka in the Mantaro Valley, by the Late Intermediate Period coca leaves from the eastern lowlands were certainly consumed by highland inhabitants. When exactly did such an exploitation of the region begin is an interesting issue that deserves further research.

Archaeological research in the Ayacucho Valley demonstrates that at the time the Nasca and the Huarpa began interacting, most Huarpa settlements were small rural villages that probably were politically and economically autonomous. These villages, originally established at least five centuries earlier to the Nasca influence, were found scattered across the entire valley, in close proximity to one another, and maintaining access to agricultural land generally found below 3,300 m a.s.l [66]. Such a site distribution strongly denotes that the Huarpa was an agriculturally oriented society [23]. Moreover, there is little or no variation at all in the ceramics found dispersed on the surface of the Huarpa settlements, suggesting that Huarpa was an egalitarian society, where the inhabitants remained neatly interconnected and shared ideas and information, including ceramic making technologies. It was to this context that some Nasca cultural traits began arriving sometime near the end of the Early Intermediate Period.

As formerly distant peoples come into contact, new ideas and new customs were readily transmitted. Such rapid adoption of foreign ideas and values carried the potential not only of challenging the cherished, perhaps centuries-old, local ideals and values, but also of altering the existent way of life. This was indeed the case of the Ayacucho Valley inhabitants following interaction with the south coast; the centuriesold village life changed rather drastically, within what appears to be only a short period of time. Indeed, Nasca cultural traits became widely distributed in the Ayacucho Valley, thus readily accessible even to the smallest Huarpa villages [66-68].

Besides the local ceramics that underwent profound change, the most notable change occurred in the settlement patterns. Shortly after the incorporation of Nasca ceramics traits, countless rural Huarpa villages were left vacant, while a few settlements that remained occupied began to grow rather rapidly [66]. With this, the until then prevalent settlement pattern, characterized by many small villages scattered throughout the valley came to conclusion as the shift occurred toward fewer but much larger settlements [67]. For instance, several small Huarpa villages were abandoned from the area what eventually became the immediate periphery of the Huari urban center [21]. Site abandonment seems to have also occurred elsewhere in the valley, including in the vicinity of Conchopata, about 25 km south from Huari [66].

As rural villages were deserted, at least two Ayacucho Valley sites began to grow: Huari and Conchopata. At the end of the Early Intermediate Period and the beginning of the Middle Horizon, these two settlements likely were rivals [26] and competed to attract more followers in order to become larger. Future research may provide similar evidence for other sections (north) of the Ayacucho Valley, but at present it is apparent that at least in two sections of the valley peoples aggregated at about the same time into two larger and competing centers, leaving the rural areas partially deserted.

An important point to be stressed here is that scholarly research argues that population aggregation in fewer but larger settlements [69] often reflects the need for defense due to imminent threat [33,69,70]. The reason for clustering is that smaller settlements are more likely to be attacked than larger settlements that are not only better defended with human made barriers, but also by much larger contingent of armed men ready to fight [71]. Furthermore, it is argued that population nucleation in one area often results in the emergence of other similar settlements in adjacent areas with the aim of maintaining their autonomy and keeping potential aggressors at bay [33]. Therefore, in a conflictive situation the best alternative to maintain one’s autonomy is to become big [33]. This was the case, for example, in areas adjacent to the Oaxaca Valley following the establishment of the well-defended and large centre of Monte Albán [72]. Available archaeological evidence suggests that something similar appear to have occurred in the Ayacucho Valley resulting in the need to aggregate in a few but much larger and easily defended settlements.

Researchers argue that violent conflict often results in the establishment of defensive settlements, provided with human made barriers such as fortifications [13,71,73]. Thus, it is asserted that fortifications are one of the most obvious indicators of violent conflict [74]. Interestingly, not a single Huarpa period settlement can be securely identified as a fortification [23,75]. However, a considerable number of Huarpa villages were established on hilltops that perhaps were preferred for their military (defensibility and visibility) advantages [53] Ñawinpukyo, an important Early Intermediate Period Huarpa settlement [22], was established on a hilltop. Therefore, it is possible that some kind of conflict, perhaps between neighbouring villages, already existed in the region prior to the emergence of centres such as Huari and Conchopata [76].

Furthermore, the clustering of larger populations in few centres often leaves extensive areas devoid of settlements [33,70,77,78]. For the area between Huari and Conchopata, besides perhaps the single early Middle Horizon site of Totorilla [21], there are no other known early Wari settlements. Moreover, Totorilla seems to represent only a brief occupation since it appears to have been eventually absorbed by either Conchopata or Huari, leaving the area vacant, perhaps as buffer zone.

Strongly suggesting that population aggregation in the region was due to growing violence, available archaeological evidence already shows that the Ayacucho Valley had become more violent following contact with the south coast. For instance, human body parts identified as trophies have been found in Huarpa contexts at Ñawimpukyo, that [79] interprets as representing conflict. Skeletal trauma signaling face-to-face combat, arguably also took place at Conchopata during Huarpa times [80]. Therefore, there is evidence that already indicates the existence of violence in the region about the time the rural Huarpa villages were abandoned. As indicated by site nucleation, during the Middle Horizon conflict in the region appears to have intensified as there is more evidence of violence in the form of skeletal trauma and iconography [80,81].

It is important to stress that during the Early Intermediate Period, the south coast was one of the few regions in the entire Central Andes where human decapitation [23] and trophy head taking were relatively widespread [82-85]. Further indicating that trophies were secured in a violent context, some valleys of the south coast had fortified settlements [53,54]. Consequently, it is apparent that the Nasca influence brought to the attention of the Ayacucho Valley inhabitants new ways of dealing with potential competitors. Ultimately, the danger of being attacked and overtaken appear to be the main reason that pushed Huarpa villagers out of their rural settlements occupied for several centuries and aggregate in a few and better defended settlements.

In a conflictive context, competing leaders of settlements such as Huari and Conchopata probably were actively engaged in concentrating their followers into their respective centers that continued to grow [38]. Such leaders likely understood that the only option to maintain autonomy was to become huge. However, in order to attract more followers, centres such as Huari had to be well defended to guarantee the safety of its residents. Interestingly, [22] asserts that Huari was a walled settlement. Then, the rural villagers who felt exposed and vulnerable left their communities for the security provided by the walls of Huari. The manner in which Huari grew, which was without following a plan [65], may further explain that rural villages were abandoned within a short period of time. As new families arrived, it appears that new suburbs were established as rapidly as possible to accommodate newcomers. Therefore, there is a growing possibility that the Huarpa villages were abandoned in a conflictive context [85].

To sum up, from the above discussion, there can be little doubt that cultural interaction incites change. Interaction between distant peoples not only allows the flow of material valuables, but also enables the spread of ideas and values that ultimately can reshape the way of life at both ends, including the existent worldviews. New ideas, previously foreign, once incorporated into a new setting can indeed alter existent conceptions about society and overall about why things are the way they are. The case explored here illustrates that following interaction in both the regions, the south coast and the central highlands changed significantly. The change appears to be more notable in the highland region, where village life was profoundly altered. Urban life emerged and with that a new political authority gained power. If previously decisions only affected the village, under the new system decisions had wider impact that eventually went beyond the Ayacucho Valley.

The overview provided here demonstrates that the interaction between the south coast and the highland valley of Ayacucho produced significant changes in ceramics, mortuary practices ad coca chewing, particularly at the latter location. Whether the two regions were linked by trade networks or the so called Nasca influence actually resulted from the arrival of south coast inhabitants is an interesting issue that must await further research. Available archaeological evidence tends to suggest that there was migration; in order to confirm it, bioarchaeological and biochemical analysis is urgently needed.

1. This is an extended and modified version of a paper presented at the 80th Annual Meeting of the Society for American Archaeology, San Francisco, California, April 15–19, 2015.

2. Huari with an H refers to the ancient Urban Center Capital of the Wari state.

3. Wari with a W refers to the Pre-Inka State Organization that flourished in the Central Andes during the Middle Horizon period.

I would like to thank my wife, Katrina J. Bettcher, for reading several drafts and providing her comments and suggestions to improve the text. Figure 4 also belongs to my wife. I also thank the editor of the journal and one anonymous reviewer for proving valuable comments and observations to improve the paper. Donald Proulx kindly shared with me Figures 5 and 6. Any shortcomings are mine alone.