Lower Paleolithic stone tool haptic exploration and sexual differences in ergonomics and finger flexion

Abstract

Cognitive archaeology combines different discipline in order to gather information about our ancestors’ behavior. In this context, material culture plays a pivotal role as an indicator oftechnological complexity and cognitive capacities. Stone tools are the most representative and complete archeological items, when dealing with Paleolithic cultural evolution. In the present survey, we investigate ergonomic and haptic variables involved in stone tool grasping, specifically when handling handaxes and worked pebbles. Grasping an object requires a combination of both biomechanical and cognitive components. The body (and in particular the hand) creates an ergonomic boundary with the handled object, and the two elements (the hand and the tool) became a single functional unit. The way in which we interact with objects can be analyzed from various perspectives and with different approaches. Some are more direct (like the study of the biomechanics of the hand) while others are more related to sensing and cognitive feedback (integration of the tool into the body schema). In previous works, we described sexual differences associated with stone tool haptic exploration and electrodermal reactions, suggesting different patterns of arousal or attentional response. These differences are apparently not associated with differences in hand size. Here, we take into consideration sexual differences associated with ergonomics and stone tool handling. In particular, we evaluated the finger joint flexion of 82 subjects during the haptic exploration of handaxes and worked pebbles. Differences between males and females are significant for both stone tool type, although with distinct grasping patterns.