IDOR Research creates a dictionary of personality adjectives, revealing cultural nuances in how Brazilians describe psychological traits

The words we use often reflect the cultural context we live in. A curious example: the Scottish language has over 400 terms to describe snow — a testament to its relevance in their daily lives. Similarly, the words we use to describe personality may reveal how we perceive ourselves and others.

With this in mind, researchers at the D’Or Institute for Research and Education (IDOR) conducted a pioneering study to organize and analyze personality traits expressed in Brazilian Portuguese. Published in the Journal of Research in Personality, the study not only refined the classification of adjectives in the language but also offered valuable insights for both psychology and artificial intelligence.

The Big Five personality traits The research is based on the widely accepted Big Five model, which describes personality along five dimensions: • Extraversion: Reflects sociability and energy. Extroverts are talkative and

outgoing; introverts are more reserved. • Agreeableness: Associated with empathy and cooperation. Highly agreeable individuals tend to be kind and trustworthy. • Conscientiousness: Indicates discipline, rule-following, organization, and responsibility. • Neuroticism: Measures emotional stability. High scorers are more prone to anxiety and stress. • Openness to experience: Reflects creativity, curiosity, and openness to new ideas.

While this model is considered universal, it was originally developed using the English language. This raises an issue: some words used to describe personality in English may not have precise equivalents in other languages. To address this, IDOR researchers conducted a series of studies to map personality adjectives in Brazilian Portuguese.

A new personality dictionary in Portuguese In the first phase, 11 experts reviewed 933 adjectives and classified them according to the Big Five. This resulted in the most comprehensive list of Portuguese-language personality adjectives to date. Previous lists contained only 25 or 64 words and were often direct translations from English, without linguistic validation.

Outdated or redundant terms were excluded. Then, a survey was conducted with 500 Brazilians of various ages, genders, and ethnicities to assess how much they identified with each adjective.

Statistical analysis revealed 136 key adjectives, distributed as follows: • Conscientiousness: 31 words • Neuroticism: 30 words • Agreeableness: 26 words • Extraversion: 25 words • Openness to experience: 24 words

The fact that conscientiousness had the most adjectives may reflect a greater cultural emphasis on discussing social rules — though not necessarily on following them. Study coordinator Dr. Ronald Fischer, a scholar of Brazilian social behavior, explains:

“People may use rule-related adjectives more often precisely because they talk about rules more — not necessarily because they follow them. It could also point to a cultural concern about breaking rules, which is part of the so-called jeitinho brasileiro. But these are just hypotheses.”

Another interesting finding: while other languages tend to have fewer words related to neuroticism, this category had the second most adjectives in Portuguese. According to Fischer, this could indicate that Brazilians are more comfortable discussing emotions — possibly influenced by a collectivist culture.

How do Brazilians see themselves? The participants’ self-perception showed agreeableness as the most valued trait (average score: 3.68 on a 5-point scale), followed by conscientiousness (3.62). This suggests that Brazilians see themselves as friendly and cooperative more than anything else.

“These findings are novel and important for personality psychology,” notes first author Gabriel Bernardes, a psychologist at CNA and PhD candidate at IDOR. “However, we must be cautious and avoid overgeneralization. More research is needed with diverse samples and cultural contexts.”

Personality and artificial intelligence The researchers also identified three linguistic dimensions that help define which Big Five category an adjective belongs to: • Valence: Whether the word has a positive or negative meaning (e.g., honest vs. selfish) • Activation: Whether it conveys energy or calmness (e.g., restless vs. serene) • Dominance: Whether it implies control (e.g., leader vs. fearful)

These findings could enhance natural language processing systems and help machines better interpret human personality through text. They also support the lexical hypothesis — the idea that the most important traits in a culture are reflected in its language.

This research represents a significant step toward understanding how language shapes our view of human personality and offers tools that can benefit both psychological science and AI development.

Written by Maria Eduarda Ledo de Abreu.