Embracing complexity. Porous cranial lesions and their paleopathological significance in two population samples from Neolithic Northern Germany

OBJECTIVE: To assess phenotypic variation of porous cranial lesions and their co-occurrence with infections of the upper respiratory apparatus and endocranial lesions, to infer disease burden in two different Neolithic socio-economic groups. MATERIALS: Human skulls of at least 111 individuals from a collective grave at Sorsum (farmers) and 30 individual biurials at Ostorf (aquatic foragers) from northern Germany (c. 3300-2900 BCE). METHODS: A new data recording protocol for scoring porous cranial lesion phenotypic variation and the assessment of inter- and intra-site frequencies and anatomical distribution. Statistical analysis of lesion frequencies and co-occurrences. RESULTS: High odds of porous cranial lesions and upper respiratory apparatus lesions co-occurrence, and of subperiosteal new bone formation of the vault (a porous cranial lesion phenotype) and endocranial lesions, are noted for both sites. Site-specific phenotypic profiles and distribution patterns differ. For Sorsum, juvenile individuals show greater porous cranial lesion frequencies and active lesions. CONCLUSIONS: Considering disease interplay is key for understanding porous cranial lesion phenotypic variation. Disease profiles can be associated with subsistence strategies. The results rule out dichotomic models (e.g. "civilization stress") and support more nuanced reconstructions of the Neolithic social-economic transformations. SIGNIFICANCE: This study emphasizes the need to adopt data recording protocols that include a wider range of porous cranial lesions to understand overlapping pathophysiological pathways. LIMITATIONS: Considerable preservation bias of the population samples. Inter-observer error is to be tested. Radiographic analyses are needed to corroborate the results. SUGGESTIONS FOR FURTHER RESEARCH: Further studies on larger assemblages from different geographical and chronological contexts are needed.