Rising interest on social-psychological effects of agile practices necessitate the development of appropriate measurement instruments for future quantitative studies. This study has constructed such instruments for eight agile practices, namely iteration planning, iterative development, continuous integration and testing, stand-up meetings, customer access, customer acceptance tests, retrospectives and co-location. The methodological approach followed the scale construction process elaborated in psychological research. We applied both qualitative methods for item generation, and quantitative methods for the analysis of reliability and factor structure (principal factor analysis) to evaluate critical psychometric dimensions. Results in both qualitative and quantitative analyses indicated high psychometric quality of all newly constructed scales. The resulting measurement instruments are available in questionnaire form and ready to be used in future scientific research for quantitative analyses of social-psychological effects of agile practices.