Modelling the possible archaeological past(s): Agent-based modelling of Harappan seal use and survival

The Harappan i.e. Indus Valley civilization, flourished in South Asia in the middle of the third millennium BCE. Among the millions of artefacts excavated from hundreds of sites, the most remarkable and extensively analysed are the ones with peculiar signs. Within this set, the most characteristic item is the Harappan seal which is at the centre of discourse in Harappan archaeology. This scholarship mostly revolves around three conjectures: (i) the signs or sign sequences indicate linguistic components and are part of a script with fixed set of signs, (ii) the ‘seals' were used as amulets or as objects of economic or administrative activities, and (iii) the primary use of seals is for creating the impressions which form `sealings'. However, the small number of actual sealings found in Harappan sites seems to challenge this last conjecture. This paper approaches the question of seal function by using agent-based modelling (ABM) to model the quantities of seals and their impressions in Harappan culture. The model seeks to suggest a hypothetical baseline for the number of sealings one might expect to find, and to see if and under which conditions the model results in the quantities of artefacts that are currently available as archaeological evidence.