The Impact of Social, Economic and Political Change in Linear and Appositional Growth of Children from the Medieval Islamic and Christian Periods of the Algarve, Portugal

• Growth can be used as a proxy for the stress experienced by the whole population. • Z-scores were used to compare the linear and appositional long bone growth of children. • No significant differences in growth were found between different Medieval time periods. • Differences in growth were found between different regions of Portugal. • Local environment has a greater impact on growth than religious or temporal differences. Archaeological data and historical research suggest that the Medieval Islamic Period (711-1249 A.D.) in Iberia was associated with conditions more favourable for child growth than the post-Islamic Christian Period (1249-1650 A.D.). This is due to agricultural prosperity, greater medical knowledge, and better hygienic practices of the former. As child growth is a sensitive indicator of environmental insults, it can be used as a proxy for the stress experienced by the whole population. The linear and appositional bone growth of 29 children (under the age of 12 years) recovered from archaeological sites in Silves and Cacela Velha - dating from the Medieval Islamic and Christian Period in the Algarve, Portugal - were compared to determine whether the environmental changes associated with the transition between these periods impacted the health and well-being of the populations. Age was estimated from tooth length. Linear growth of all long bones and the appositional growth of the femur and humerus at the midshaft were compared between periods using z-scores. Bone growth deficits were found among the medieval children in all samples. Overall, Islamic Period children had slightly greater growth deficits than Christian Period children, although these differences were not statistically significant. This finding suggests that neither Medieval Period was more favourable for growth. Statistically significant differences in appositional growth were found between the Medieval Santarém and Algarve populations, suggesting these differences to be related to the local environment, rather than religious or temporal differences within the Algarve or other regions of Portugal.