The Big Five Inventory (BFI) is a self-report measure assessing the five high-order personality traits: Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness. As part of the International Sexuality Description Project, the BFI was translated into 28 languages and administered to 17,837 individuals from 56 nations. The resulting cross-cultural data set was used to address three main questions: Does the factor structure of the English BFI fully replicate across cultures? How valid are the BFI trait profiles of individual nations? And how are personality traits distributed throughout the world? The five-dimensional structure was robust across major regions of the world. Trait levels were related in predictable ways to self-esteem, sociosexuality, and national personality profiles. People from the geographic regions of South America and East Asia were significantly different in openness from those inhabiting other world regions. The discussion focuses on limitations of the current data set and important directions for future research. Keywords: personality traits; cross-cultural psychology; Big Five Many popular psychological assessment instruments, originally developed in English, have been translated into numerous languages and are now commonly used throughout the world (e.g., Butcher, Lim, & Nezami, 1998; Nichols, Padilla, & Gomez-Maqueo, 2000). Most of these translations were made with an explicit or at least tacit assumption that the core psychological constructs assessed by the measures substantively transcend human language and culture. Some researchers have expressed concern with this assumption (F. M. Cheung & Leung, 1998; Misra, 1994; Shweder, 1990) and have questioned whether the uncritical extension of “Western” ways of thinking to the rest of the world should serve as standard practice in psychological science (cf. Church, 2000). Although many of these issues remain unresolved (Triandis, 1997), what seems clear is that when psychological measures are simply translated from their original English and etically imported “as is” into diverse cultures, comparing the assessment results from different cultures becomes highly problematic (Brislin, 1993; van de Vijver, 2000). ## PROBLEMS IN COMPARING PERSONALITY TRAIT SCORES ACROSS CULTURES For psychologists seeking to investigate personality traits across cultures, one of the more vexing problems has centered on whether personality trait scales possess conceptual and functional equivalence across cultures (Brislin, 1993; Lonner, 1979; Triandis, 1994; van de Vijver & Leung, 2000). Particularly troublesome has been establishing whether the mean scores across different cultures show metric or scalar equivalence (Byrne & Campbell, 1999; LittleThe Big Five Inventory (BFI) is a self-report measure assessing the five high-order personality traits: Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness. As part of the International Sexuality Description Project, the BFI was translated into 28 languages and administered to 17,837 individuals from 56 nations. The resulting cross-cultural data set was used to address three main questions: Does the factor structure of the English BFI fully replicate across cultures? How valid are the BFI trait profiles of individual nations? And how are personality traits distributed throughout the world? The five-dimensional structure was robust across major regions of the world. Trait levels were related in predictable ways to self-esteem, sociosexuality, and national personality profiles. People from the geographic regions of South America and East Asia were significantly different in openness from those inhabiting other world regions. The discussion focuses on limitations of the current data set and important directions for future research. Keywords: personality traits; cross-cultural psychology; Big Five Many popular psychological assessment instruments, originally developed in English, have been translated into numerous languages and are now commonly used throughout the world (e.g., Butcher, Lim, & Nezami, 1998; Nichols, Padilla, & Gomez-Maqueo, 2000). Most of these translations were made with an explicit or at least tacit assumption that the core psychological constructs assessed by the measures substantively transcend human language and culture. Some researchers have expressed concern with this assumption (F. M. Cheung & Leung, 1998; Misra, 1994; Shweder, 1990) and have questioned whether the uncritical extension of “Western” ways of thinking to the rest of the world should serve as standard practice in psychological science (cf. Church, 2000). Although many of these issues remain unresolved (Triandis, 1997), what seems clear is that when psychological measures are simply translated from their original English and etically imported “as is” into diverse cultures, comparing the assessment results from different cultures becomes highly problematic (Brislin, 1993; van de Vijver, 2000). ## PROBLEMS IN COMPARING PERSONALITY TRAIT SCORES ACROSS CULTURES For psychologists seeking to investigate personality traits across cultures, one of the more vexing problems has centered on whether personality trait scales possess conceptual and functional equivalence across cultures (Brislin, 1993; Lonner, 1979; Triandis, 1994; van de Vijver & Leung, 2000). Particularly troublesome has been establishing whether the mean scores across different cultures show metric or scalar equivalence (Byrne & Campbell, 1999; Little