RHETORICAL EVOLUTION OF BRAZILIAN PRESIDENTIAL SPEECHES: ANALYSIS OF TERMS, LEGIBILITY, AND LEXICAL DIVERSITY (1985–2022)

Abstract

This study analyzes the evolution of the rhetoric of Brazilian presidential speeches from 1985 to 2022—a period marked by significant political, social, and technological transformations in Brazil. A total of 6,069 speeches, drawn from the Library of the Presidency of the Republic and a Kaggle repository, were examined using readability metrics (average number of words per sentence) and lexical diversity (TTR – Type-Token Ratio). The analysis reveals a trend toward rhetorical simplification over the decades, particularly from the administration of Luiz Inácio Lula da Silva onward, with shorter, more accessible speeches. Nonetheless, lexical diversity remained high, indicating that presidents continued to address a broad range of topics, balancing structural simplicity with thematic depth. These findings highlight how presidential discourse has adapted to the demands of a rapidly changing political and media environment, shaped by the rise of social networks and the fragmentation of public attention. They demonstrate that, over nearly four decades, presidential rhetoric reflects both the country’s sociopolitical conditions and the strategies leaders employ to consolidate legitimacy and popular support.