Classic Maya bloodletting and the cultural evolution of religious rituals: quantifying patterns of variation in hieroglyphic texts

Abstract

Religious rituals that are painful or highly stressful are hypothesized to be costly signs of commitment essential for the evolution of complex society. Yet few studies have investigated how such extreme ritual practices were culturally transmitted in past societies. Here, we report the first study to analyze temporal and spatial variation in bloodletting rituals recorded in Classic Maya (ca. 250-900 CE) hieroglyphic texts. We also identify the sociopolitical contexts most closely associated with these ancient recorded rituals. Sampling an extensive record of 2,480 hieroglyphic texts, this study identifies every recorded instance of the logographic sign for the word ch'ahb' that is associated with ritual bloodletting. We show that documented rituals exhibit low frequency whose occurrence cannot be predicted by spatial location. Conversely, network ties better capture the distribution of bloodletting rituals across the southern Maya region. Our results indicate that bloodletting rituals by Maya nobles were not uniformly recorded, but were typically documented in association with antagonistic statements and may have signaled royal commitments among connected polities.

Figure 1. Bloodletting scene from Yaxchilan Lintel 17.

This image of Classic Maya bloodletting depicts a royal man using a stingray spine to pierce his penis and a noble woman pulling a thorny vine through her tongue in ritual acts of self-sacrifice. Drawing by Ian Graham , Yaxchilan, Lintel 17. © President and Fellows of Harvard University, Peabody Museum of Archaeology and Ethnology, 2004.15.6.5.16. Digital file #101240031.

Figure 2. Bowl containing instruments used in Classic Maya bloodletting rituals.

From Yaxchilan Lintel 25. Detail of drawing by Ian Graham , Yaxchilan, Lintel 25, front edge. © President and Fellows of Harvard University, Peabody Museum of Archaeology and Ethnology, 2004.15.6.5.22. Digital file #101240034.

Figure 3. Detail of ZYC graphemes showing variants of the ch’ahb’ bloodletting glyph.

Drawing by Matthew G. Looper .

Figure 4. Location and name of southern Maya lowland sites included in the study.

Red dot indicates sites that record the ch’ahb’ bloodletting glyph and black dot indicates sites where no reference to ch’ahb’ bloodletting has been found. Size of red dot refers to the relative abundance of dated monuments that record bloodletting rituals.

Figure 5. Relative frequency of dated monuments with ch’ahb’ bloodletting glyph in each 20-year k’atun period.

References to bloodletting rituals exceed 15% during two k’atun periods, 9.8.0.0.0 (593–613 CE) and 9.13.0.0.0 (692–712 CE).

Figure 6. Temporal distribution of dated monuments, political statements, and ch’ahb’ bloodletting statements included in the study.

X-axis is divided into 20-year increments known as k’atun periods in the Maya Long Count calendar system. Note the overall low frequency of ch’ahb’ bloodletting statements in comparison to the number of dated monuments during each k’atun period.

Figure 7. Estimates for the negative binomial mixed model effects including the confidence intervals.

Figure 8. Bubble graph of standardized G_i* scores at a lag distance of 150 kilometers.

Bubble area is proportional to |G_i*|. Red bubbles represent positive G_i* scores, where ch’ahb’ bloodletting rituals are recorded. White bubbles represent negative G_i* scores, where there are no bloodletting records. Sites labeled with ID number have significant G_i* scores and correspond to the site names and IDs in Figure 4.

Figure 9. Network graph showing the sociopolitical ties between sites partitioned by the presence of ch’ahb’ bloodletting statements.

Sites labeled in red indicate the presence of ch’ahb’ (light pink indicates absence). The nodes are plotted using their geographic coordinates. Site IDs correspond to the names listed in Figure 4.