Table 2.

Neurobiological substrates of monogamy in primates

Measure	Behavioral Trait
	Pair living	Mate-directed sociality	Partner preference	Mate guarding	Separation distress	Social buffering	Paternal care	References
Sex-steroids
Testosterone c		↑		↑			↓	(Nunes et al., 2000, 2001; Prudom et al., 2008; Ross & French, 2011; Ross et al., 2004; Toni E. Ziegler et al., 2011, 2005; T. Ziegler & Snowdon, 2000)
Testosterone agonist		↑/↓					0	(Kendrick & Dixson, 1985)
Estradiol c		↑						(L.J. Digby, 1999; Kendrick & Dixson, 1983; Toni E. Ziegler et al., 2005)
Estradiol agonist							↑	(Kendrick & Dixson, 1985)
Glucocorticoids
Cortisol c		↑		↑/0	↑	↓	↓	(Fisher-Phelps et al., 2015; Hennessy, Mendoza, Mason, & Moberg, 1995; Nunes et al., 2001; Ross & French, 2011; Ross et al., 2004; Rukstalis & French, 2005; Adam S. Smith et al., 2011)
CRH-1 antagonist					↓			(J. A. French et al., 2007)
Neuropeptides
Oxytocin c		↑		0				(Finkenwirth et al., 2015; Fisher-Phelps et al., 2015; C.T. Snowdon et al., 2010)
Oxytocin agonist		↑	↑			0	↑	(Cavanaugh et al., 2015, 2014; Mustoe et al., 2015; Saito & Nakamura, 2011; J. H. Taylor & French, 2015)
Oxytocin antagonist		↓/0	0			↓	0	(Cavanaugh et al., 2016, 2014; Mustoe et al., 2015; Adam S. Smith et al., 2010)
Vasopressin c				↑				(Fisher-Phelps et al., 2015)
Vasopressin agonist			↑				↑	(Jarcho et al., 2011; J. H. Taylor & French, 2015)
Dopamine
Neural activity in the reward system	↓							(K. L. Bales et al., 2007)
Opioids
MOR agonist		↓						(Ragen et al., 2015, 2013)
KOR agonist					0			(Ragen et al., 2015)
KOR antagonist					↓			(Ragen et al., 2015)
Nonspecific antagonist		↓				↑		(Ragen et al., 2013)

Note.

^c= correlation of measured hormone concentration with social feature.

↑ = increases social feature; ↓ = decreases social feature; 0 = no effect on social feature. Cells without an entry indicate no data have been published.