 In recent years, philosophers of science have become increasingly interested in psychometrics and the concept of validity. One debate concerns the ontological status of latent psychological attributes. Denny Borsboom has argued against operationalism about latent attributes, and in favour of defining validity in a manner that embraces realism: “a test is valid for measuring an attribute if and only if a) the attribute exists, and b) variations in the attribute causally produce variations in the outcomes of the measurement procedure” (2005: 150; see also Hood 2009, 2013; Feest 2020). Elina Vessonen has defended a moderate form of operationalism about psychological attributes, and argued that moderate operationalism is compatible with a cautious type of realism (2019). Another recent discussion focuses on the justification for construct validation procedures. According to Anna Alexandrova, construct validation is in principle a justified methodology, insofar as it establishes coherence with theoretical assumptions and background knowledge about the latent attribute. However, Alexandrova notes that in practice psychometricians who intend to measure happiness and well-being often avoid theorizing about these constructs, and instead appeal to respondents’ folk beliefs. This defeats the purpose of construct validation and turns it into a narrow, technical exercise (Alexandrova and Haybron 2016; Alexandrova 2017; see also McClimans et al. 2017).