“…In this aspect, HPCs are different from natural kinds (which have necessary and sufficient features), but like natural kinds, they are non-arbitrary. Recent work suggests that a wide range of psychological constructs may best be understood as HPCs: mental disorders (Borsboom, 2017;Kendler et al, 2011), personality characteristics (Mõttus & Allerhand, 2017), attitudes (Dalege et al, 2015), and intelligence (van der Maas et al, 2006;van der Maas, Kan, Marsman, & Stevenson, 2017).…”