I have chosen to include a "further reading" list rather than properly referencing my material and adding a reference list because not everyone has access to the papers I would reference and I find it a bit annoying to be constantly referred to material I can't access. So below is a list of relevant papers I would reference. If you have trouble tracking them down, feel free to contact me and ask me about it. My e-mail address is on the "About Me" page and on the survey page. Try Google Scholar first, though! It will be quicker.
Bateson, M. and S. Matheson (2007). "Performance on a categorisation task suggests that removal of environmental enrichment induces' pessimism'in captive European starlings (Sturnus vulgaris)." Animal Welfare 16(Supplement 1): 33-36.
Bogdan, R. and D. Pizzagalli (2008). "The heritability of hedonic capacity and perceived stress: a twin study evaluation of candidate depressive phenotypes." Psychological medicine 39(02): 211-218.
Brilot, B., L. Asher, et al. "Stereotyping starlings are more ‘pessimistic’." Animal Cognition 13(5): 721-731.
Brydges, N., M. Leach, et al. (2010). "Environmental enrichment induces optimistic cognitive bias in rats." Animal Behaviour 81(1): 169-174.
Burman, O., R. Parker, et al. (2008). "A spatial judgement task to determine background emotional state in laboratory rats, Rattus norvegicus." Animal Behaviour 76(3): 801-809.
Coppens, C. and S. de Boer (2010). "Coping styles and behavioural flexibility: towards underlying mechanisms." Philisophical Transactions of the Royal Society B 365: 4021-4028.
Doyle, R., A. Fisher, et al. (2010). "Release from restraint generates a positive judgement bias in sheep." Applied Animal Behaviour Science 122: 28-34.
Harding, E., E. Paul, et al. (2004). "Animal behaviour: cognitive bias and affective state." Nature 427(6972): 312.
Horváth, Z., B. Igyártó, et al. (2007). "Three different coping styles in police dogs exposed to a short-term challenge." Hormones and behavior 52(5): 621-630.
John, O. P., Naumann, L. P., & Soto, C. J. (2008). Paradigm Shift to the Integrative Big-Five Trait Taxonomy: History, Measurement, and Conceptual Issues. In O. P. John, R. W. Robins, & L. A. Pervin (Eds.), Handbook of personality: Theory and research (pp. 114-158). New York, NY: Guilford Press.
Koolhaas, J., S. Korte, et al. (1999). "Coping styles in animals: current status in behavior and stress-physiology." Neuroscience & Biobehavioral Reviews 23(7): 925-935.
Koolhaas, J. M., S. F. De Boer, et al. (2010). "Neuroendocrinology of coping styles: Towards understanding the biology of individual variation." Frontiers in Neuroendocrinology 31(3): 307-321.
Ley, J., P. Bennett, et al. (2008). "Personality dimensions that emerge in companion canines." Applied Animal Behaviour Science 110(3-4): 305-317.
Lindström, L. (2010). "Performance of laying hens in a cognitive bias task."
Matheson, S., L. Asher, et al. (2008). "Larger, enriched cages are associated with 'optimistic' response biases in captive European starlings (Sturnus vulgaris)." Applied Animal Behaviour Science 109(2-4): 374-383.
Mendl, M., J. Brooks, et al. (2010). "Dogs showing separation-related behaviour exhibit a "pessimistic cognitive bias." Current Biology 20(19).
Mendl, M., O. Burman, et al. (2009). "Cognitive bias as an indicator of animal emotion and welfare: Emerging evidence and underlying mechanisms." Applied Animal Behaviour Science 118(3-4): 161-181.
Pomerantz, O, J Terkel, SJ Suomi, A Paukner (2012) Stereotypic head twirls, but not pacing, are related to a 'pessimistic'-like judgment bias among captive tufted capuchins (Cebus apella). Animal Cognition 15(4): 689-698
Reefmann, N., B. Wechsler, et al. (2009). "Behavioural and physiological assessment of positive and negative emotion in sheep." Animal Behaviour 78(3): 651-659.
Rygula, R., Papciak, J., & Popik, P. (2013). Trait Pessimism Predicts Vulnerability to Stress-Induced Anhedonia in Rats. Neuropsychopharmacology 38(11): 2188-96.
Svartberg, K. (2002). "Shyness-boldness predicts performance in working dogs." Applied Animal Behaviour Science 79(2): 157-174.
Svartberg, K. (2005). "A comparison of behaviour in test and in everyday life: evidence of three consistent boldness-related personality traits in dogs." Applied Animal Behaviour Science 91(1-2): 103-128.
Svartberg, K. and B. Forkman (2002). "Personality traits in the domestic dog (Canis familiaris)." Applied Animal Behaviour Science 79(2): 133-155.
Wilson, S., A. B. Clark, et al. (1994). "Shyness and boldness in humans and other animals." Trends in Ecology & Evolution 9(11): 442-446.
Last updated: October 2013