Clarke, M. R., Kaplan, J. R., Bumsted, P. T. et al. 1986. Social dominance and serum testosterone concentration in dyads of male Macaca fascicularis. Journal of Medical Primatology 15, 419-432.

Of 16 pairs, five dyads had to have their composition changed at some point [of the 8-month study period] owing to excessive fighting. [Pair formation procedure is not described.] Testosterone concentration and dominance were associated according to the type of dyadic social relationship. If the dyadic relationship was one of clear dominance , no association was found between rank and testosterone, but following reversals in dominance or when dominance was contested by the subordinate animal, the higher ranking partner had higher testosterone concentrations significantly more frequently.