Besides climate change, the loss of biodiversity due to human activities marks another planetary boundary that we are currently crossing. Cross-culturally invariant measurement instruments are urgently needed to monitor and evaluate the effects of global and national programmes to halt further biodiversity loss. Based on data from Brazil, China, Colombia, India, Indonesia, Kenya, Mexico, Peru, South Africa, Vietnam, and Germany, we tested the cross-cultural invariance of scales operationalizing an extended theory of planned behaviour for the prediction of biodiversity-conserving behavioural intentions. Cross-cultural invariance was tested using the multi-group confirmatory factor analysis and the alignment optimization approaches, whose methodological setup is described and discussed. Results for both methods indicate metric and partial scalar invariance of the used scales, which means that both regression coefficients and latent means can be compared across countries. The resulting scales can be used to both monitor biodiversity-related behavioural intentions and their predictors across different cultures and evaluate interventions to increase these intentions.
