Appendix 2. Trait rating instruments used in reviewed non-human primate personality research, with the most commonly used tools presented first.

Name of Trait Rating Instrument	Proportion of Trait Rating studies (%)	Reference
Hominoid Personality Questionnaire (HPQ)	41	(Weiss, 2009, 2017)
Maddingley Questionnaire	13	(Stevenson-Hinde & Zunz, 1978)
Biobehavioural Assessment (BBA) Temperament Scale	11	(Capitanio et al., 2005)
Freeman Questionnaire	7	(Freeman et al., 2013)
Undefined Trait Rating Assessment	7	(Fernández-Lázaro et al., 2019)
Gorilla Behavioural Index	7	(Kuhar et al., 2006)
Five Factor Model	2	(Robinson et al., 2017)
BIAZA Behavioural Profiling Guidelines	2	(Ward & Melfi, 2013)
Capuchin Personality Inventory	2	(Uher & Visalberghi, 2016)
Macaque Personality Inventory	2	(Uher, Werner & Gosselt, 2013)