Kava drinking and its role in cultural evolution

Did the consumption of the mind-altering beverage kava facilitate the emergence of complex, hierarchical societies in Oceania?

To the Point

• Drunk hypothesis: Scholars have argued that intoxication facilitated the rise and maintenance of large-scale complex societies by promoting social bonding and increasing cooperation.
• Kava in Oceania: Before the arrival of alcohol during the colonial period, kava was the main psychoactive substance in Oceania.
• Coevolutionary models: An analysis of 83 Oceanic-speaking societies found no evidence of coevolution between kava drinking and sociopolitical complexity.

Scholars have long debated whether our desire to get drunk and high is evolutionarily adaptive or maladaptive. Based on the ancient and widespread human use of psychoactive substances, some argue that intoxication has played an important role in our cultural evolution. By promoting social bonding, increasing cooperation, and enhancing creativity, intoxication has been claimed to facilitate the emergence of large-scale complex societies.

"This 'drunk hypothesis' has so far mainly emphasized the role of alcoholic beverages,” says Václav Hrnčíř from the Max Planck Institute for Evolutionary Anthropology in Leipzig, who led a new study focusing on the traditional Pacific drink kava. “After my colleagues and I recently found that drinking alcohol could indeed have a positive effect on the rise of political complexity on a global scale, it was a logical step to investigate other mind-altering drugs as well. And the region of Oceania is a good test case because alcohol was unknown there until the time of European contact.”

Kava and sociopolitical complexity

Instead of alcohol, many Oceanic societies have consumed kava, a mind-altering drink prepared by infusing the chewed or ground roots of the plant kava (Piper methysticum) with cold water. Like some other drugs, kava has played an important role in the religious, social and political spheres. For example, in Fiji, kava (or yaqona) is drunk to communicate with gods and ancestral spirits, celebrate significant life events, welcome guests, and settle disputes, both in interpersonal and intergroup relationships.

The traditional kava ceremonies serve to strengthen social bonds and reinforce prevailing political and social hierarchies. Strict protocols based on social status and titles govern where people sit, who can drink kava and in what order. Participation in these rituals and excessive kava consumption are important for both achieving prestige within the community and fostering social alliances.

No evidence of coevolution

While the cultural significance of kava in Oceanic societies is well known, previous studies have not explored its potential as an active driver of sociopolitical complexity. “Therefore, we collected and analyzed ethnographic data from 83 Oceanic-speaking societies on the presence of traditional kava drinking and two commonly used measures of cultural complexity – political centralization and social stratification,” says Oliver Sheehan, a co-author of the study from the University of Auckland in New Zealand.

To understand the association between kava and both sociopolitical traits, the authors modelled their coevolution on a phylogenetic tree of Austronesian languages. “This method enabled us to infer causal directionalities in the cultural evolution of kava drinking and sociopolitical complexity,” explains Scott Claessens, a co-author from the University of Kent in the UK.

However, the models showed no evidence of coevolution between kava drinking and either of the two sociopolitical traits. “This means that kava drinking was not a major factor explaining the rise of cultural complexity in Oceania," concludes the senior author, Russell Gray. The results thus challenge the broad version of the "drunk hypothesis", indicating that not all social drugs played the same cultural evolutionary role.