Mesolithic harpoons are structurally complex weapon points and significant sources of archaeological information. Nonetheless, separating different types of information inherent in harpoon point shapes (e.g., aspects relating to mechanical performance, personal or group craft variation and chronology) using descriptive approaches is difficult. In this study, we employed an exploratory geometric morphometric approach to the analysis of 28 Mesolithic harpoon points, and 144 undated harpoon points from the circum-Baltic Sea area in order to retrieve both functional and spatiotemporal information. By analyzing harpoon structure statistically through (i.) a shape proxy (harpoon silhouette) and (ii.) harpoon sub-structures (barbs), we have been able to reveal information related to both variation in shape convention and functional constraints. Barb shape results revealed statistically significant chronological and geographical groupings with spatiotemporal barb-shape trajectories made visible and objective evaluation of how barb-shape conventions impacted functional variation. In addition, harpoon silhouette shape distributions were shown to have potential as sources for robust artifact classifications in relation to functional constraints and raw-material engagement. These results suggest that morphometric approaches similar to the ones we have employed offer promising ways of addressing specific archaeological questions in the context of harpoon point shapes and, more generally, other complex weapon point forms.

Stone Age hunter-gatherer weapon studies should hold a more central position within war studies since the vast majority of human weapons ever in existence were once used by these types of societies. Among these weapons, the projectile, or the weapon point, is arguably the most numerous and well-studied in both archaeological and ethnographical contexts. However, from a warfare and conflict perspective, the study of weapon points in Stone Age and hunter-gatherer societies is beset by two substantial and intertwined issues: (i) the problem of categorizing and defining violent activities and (ii) the problem of identifying functions for weapon points. 

The thesis of this paper is that by turning to the ecological scale, i.e. the epistemology and ontology of Ecological Psychology and Dynamic Systems Theory (EP DST), these issues can be approached constructively. The ecological scale offers a consistent relational framework to quantitatively address weapon point property variation, covariation, historical and practical specificity, as well as experimental principles to quantitatively study emergent patterns in human-weapon point-environment relations. Archaeological studies and experiments with EP DST principles could potentially reveal how organisms, environment and emergent patterns affect the properties of a weapon point in traditional hunter-gatherer societies, given the typically intimate relationship between craft, body and usage. How this could be accomplished is exemplified with the Northern Eurasian inset point, an object that has been found in association with human bodies in Mesolithic Scandinavia. Hence, through EP DST perspectives and approaches, weapons points can be re-socialised in order to reveal their more specific or contextual conflict related dimensions.

Modern geometric techniques offer significant potential to uncover the worlds in which weapons were created, worlds shaped by specific environmental conditions and knowledge systems transmitted through established networks. We analysed the morphology of Mesolithic harpoon points from Eastern Middle Sweden to explore developments in craft and hunting techniques across the circum-Baltic Sea area, and to investigate if specific morphological traits are linked to regional environmental and faunal changes. We identified and separately analysed structural elements of the harpoon points, barbs, proximal and distal parts, and full-body silhouettes using geometric morphometrics and direct radiocarbon dating. Our results show that barb and proximal part shapes changed during the transition from the Early to the Middle Mesolithic in Eastern Middle Sweden which fits into broader superregional trends in craft and hunting techniques. In contrast, the width of the proximal part remained relatively stable throughout the Mesolithic, indicating continuity in regional crafting traditions and specific environmental conditions. The shapes of distal parts and full-body silhouettes correlate with the regional availability of large terrestrial prey. This study highlights the potential of geometric morphometric analysis to study morphological changes in harpoon points and to shed light on the multiple influences that shaped Mesolithic hunting weapons.

The influence of experiences with weapon use on subsequent modifications and the creation of weapon points is rarely addressed in experimental archaeology. Addressing this problem requires methods that relate fine-grained characteristics of weapon points to the situated experiences of experimental participants. In this pilot study, we combine an activity-based experiment informed by ecological psychology and dynamic systems theory with continuum mechanical simulations and geometric morphometrics to investigate whether kinematic and kinetic information perceived during weapon point use can be traced in subsequent modification tasks.

The results demonstrate that specific kinetic information from spear use can be identified through mathematical modeling and linked to subtle variations in the outlines of the weapon points produced by participants. This suggests that fine-scale morphological variation may reveal ecological information derived from the environments in which it is used. We argue that integrating human action, mechanical modeling, and morphometric analysis provides a promising methodological framework for exploring how functional experience contributes to weapon point variability beyond traditional archaeological approaches.