# Assessing subclinical psychopathological and personality traits in a small-scale subsistence society

## TL;DR

This paper explores whether psychiatric traits are linked to Western lifestyles or are part of human variation by developing a culturally adapted tool for assessing mental health in the Tsimane' society.

## Contribution

The study introduces a culturally sensitive instrument for measuring subclinical psychiatric and personality traits in a small-scale society.

## Key findings

- A 117-item instrument was developed for the Tsimane' covering traits like autism, depression, and anxiety.
- The tool was adapted through collaboration with local assistants and translated into Tsimane' for cultural relevance.
- The approach provides a model for studying mental health in non-Western contexts.

## Abstract

Are psychiatric conditions linked to Western, Educated, Industrialized, Rich, and Democratic (WEIRD) lifestyles, akin to other “diseases of civilization”, or have they always been part of human variation? Are psychiatric traits always harmful and selected against, or can they be neutral or adaptive in some contexts? Addressing such core questions in evolutionary psychiatry requires examining and quantifying psychiatric symptoms and their subclinical manifestation in radically different cultural and ecological settings, such as small-scale subsistence societies. Available tools designed for the global North are often ill-suited for these communities, failing to translate and to reflect culturally-specific experiences. Here, we present a multi-stage approach for assessing subclinical psychopathological and personality traits among the Tsimaneʼ, an Indigenous forager-horticulturalist population in lowland Bolivia.

Building on established questionnaires, we reviewed over 400 items through extensive collaboration with local research assistants, focus groups, and cognitive interviews. We grounded each item in culturally relevant examples and translated them into Tsimaneʼ, ensuring both conceptual accuracy and comprehensibility.

The final instrument consists of 117 items associated in Global North settings with autism spectrum disorder, attention deficit hyperactivity disorder, obsessive-compulsive disorder, schizotypy, depression, anxiety, trauma, substance use, and personality.

This study provides a model for developing culturally sensitive tools to measure mental health traits in small-scale societies. It contributes to evolutionary psychiatry by laying the groundwork for quantifying subclinical psychopathology and personality traits, enabling rigorous tests of evolutionary hypotheses.