If you want to learn about real behaviour, measure real behaviour.

We argue that research aiming to understand or change human behavior must measure real behavior, not just behavioral intentions, to draw valid conclusions. The work highlights the well-established gap between people's intentions and behavior across various tourism and hospitality contexts. Methodologically, we encourage authors not to rely on behavioral intentions and instead measure real behavior. We provide an overview of methods available to capture real behavior either automatically or manually in tourism contexts. The article also introduces a special issue in the Journal of Sustainable Tourism that showcases the measurement of real environmentally significant tourist behavior using diverse methods, such as biometric techniques, big data analytics, field observations, and experiments. We conclude by discussing five issues that prevent studies form drawing causal conclusions about behavior, namely, (i) reliance on behavioral intentions; (ii) a sample that does not reflect the population of interest; (iii) errors in measuring latent psychological constructs; (iv) consumer hypocrisy and social desirability bias; and (v) situational factors and habits. By advocating for a transition towards measuring real behavior, the article and the special issue aim to increase the validity and impact of research seeking to understand human behavior and drive effective behavior change for addressing global challenges. Highlights: Much tourism research aims to understand or change behavior. Yet, behavior is not routinely measured, limiting the validity of findings. This article discusses the many possible approaches to capturing real behavior. This article outlines the most valid research design to study behavior (change). This article introduces the special issue on measuring real behavior. [ABSTRACT FROM AUTHOR]