*Fairbanks, L. A., Jorgensen, M.J., Bailey, J. N., Breidenthal, S. E., Grzywa, R., & Laudenslager, M. L. (2011). Heritability and genetic correlation of hair cortisol in vervet monkeys in low and higher stress environments. Psychoneuroendocrinology, 36(8), 1201-1208. doi:10.1016/j.psyneuen.2011.02.013.