The "Messaging Motivations Questionnaire" ("MMQ") is a concise 8-item measure, which consists of two subscales capturing people's typical motivations to text. The MMQ was developed through focus groups and item analysis based on a pilot study, followed by a larger validation study involving a sample of 982 young adults. Factor analyses supported a 2-factor structure, yielding highly reliable scale scores: "Escape," characterized by the wish to escape or avoid internal or external stimuli when texting; and "Express," characterized by the use of text messaging over richer forms of communication media to facilitate self-expression. Criterion validity of the MMQ scores was established using measures of problematic smartphone use, social anxiety, self-esteem, and the Big Five dimensions of personality. Women exhibited slightly higher scores on both subscales. There were no race/ethnicity-related MMQ score differences, and marginal age-related differences. The MMQ is a promising tool for counselors to better understand and discuss their young adult clients' texting behaviors, as well as for future research focused on texting behavior and its consequences.