Advances in artificial intelligence (AI) hold promise for clarifying personality disorder (PD) models, research methodology, understanding, and clinical treatment. This study models personality and personality pathology using natural language. A representative community sample of N = 1,409 older adults from St. Louis (33% Black, 65% White, and 2% other) completed life narrative interviews lasting on average 20 min. Language from the interviews was then used to train and test language-based personality models on scores from the NEO-Personality Inventory-Revised and the Structured Interview for DSM-IV Personality. Criteria measures were used for multimethod construct validation of the language models including self-report measures of physical functioning and depressive symptoms and informant-report measures of personality, general health status, and social functioning. Language models were developed using fine-tuning of the parameters of the RoBERTa language model, BERTopic topic modeling, and Linguistic Inquiry and Word Count. Fine-tuned RoBERTa models predicted personality scores in testing data above r = .40, approaching what is considered a large effect size for convergent validity tests between two self-reports of the same construct. Life narrative language was more readily mapped onto the five-factor model trait domains than onto DSM PD categories, aside from moderate support for borderline pathology. The language-based five-factor model scores were supported by multimethod criteria correlations including informant-report personality scores in the testing data. Findings demonstrate the potential promise of language-based AI to refine conceptual frameworks of PD and provide automatic personality assessment and prediction in research and clinical practice. (PsycInfo Database Record (c) 2025 APA, all rights reserved).