Table 2: Summary of Methodology to Determine Social Rank:

Reference for the methodology employed to determine social status.

Section	Reference	Summary	Organism	Sex	Dominance Measurement
Cortical Top-down Facilitation of Social Dominance	[40]	Dominants and subordinates have differential gene expression in mPFC	C57BL/6J Mice	Male	Tube Test
	[41]	mPFC lesion reduces rank	Long Evans Rats	Male	Observations of agnostic behavior in semi naturalistic environment
	[33]	Synaptic efficacy within the mPFC bidirectionally controls social rank	C57BL/6J Mice	Male	Tube test (primary), visible Burrow System, observations of agnostic behavior, barber test, ultrasonic vocalizations, urine marking, ultrasound events
	[42]	Optogenetic activation of mPFC caused increased rank	C57BL/6J mice	Male	Tube test, warm spot competition
	[45]	Dominants had to maintain rank for 14 days to be protected from social defeat	Syrian Hamsters	Male	Agnostic behavior observations during resident intruder from daily social encounters in paired dyads
	[46]	Dominants display more active coping behaviors following social defeat		Male	Agnostic behavior observations during resident intruder from daily social encounters in paired dyads
	[48]	Dominants had increased cFOS in BLA projections from mPFC	Syrian Hamsters	Male	Agnostic behavior observations during resident intruder from daily social encounters in paired dyads
	[49]		Syrian Hamsters	Male	Agnostic behavior observations during resident intruder from daily social encounters in paired dyads
	[50]	Activating BLA projections from mPFC increased active behaviors to social defeat in subordinates only	Syrian Hamsters	Male	Agnostic behavior observations during resident intruder from daily social encounters in paired dyads
	[53]	Genetic expression differences in the BLA between dominants and subordinates	Syrian Hamsters	Male + Female	Agnostic behavior observation from a single day of resident intruder pairings
Mesolimbic Dopamine circuitry in dominance and aggression	[64]	Dominants had altered dopamine availability across multiple brain regions	Anolis carolinensis Lizard	Males	Assessment of physical markings of social status (eye spots)
	[66]	Increased cFOS in VTA of dominants associated with higher aggression	Syrian Hamsters	Male	Assessment of either aggression and/or flank marking or submissive behavior during a social interaction
	[68]	Optogenetic stimulation fo VTA DA neurons increased rank	Long Evans Background Transgenic Rats	Male	Performance in social competition tasks (palatable reward and water competition)
	[72]	Diazepam administration to VTA did not alter rank	Wister Rats	Male	Agnostic behavior observation in established dyads
	[75]	Differences in NAc metabolism between ranks	C57BL/6J Mice	Male	Tube test, urine marking, agnostic behavior observation
	[76]	Treatment of dominants with mitochondria boosting supplement improved stress outcome	C57BL/6J Mice		Tube Test
	[78]	Downregulation or knockout of glucocorticoid receptors increased rank.	Wistar Rats		Agnostic behavior observation in established dyads
	[90]	SES and social status positivity correlated with D2/D3 receptor availability		Male and Female	Socioeconomic status (SES) measured with the Hollingshead scale
	[92]	Dominants had increased D2/3 binding in NAC	Listar Hooded rats	Male	Resource competition task, tube test
	[93]	No difference between ranks when individually housed. Dominants had more D2/D3 receptor availability	Cynomolgus monkeys	Male	Observations of agnostic behavior in group housing condition
	[94]	No difference between ranks when individually housed. Dominants had more D2/D3 receptor availability	Cynomolgus monkeys	Female	Observations of agnostic behavior in group housing condition
	[95]	Subordinates who then became dominant had increased D2/D3 receptor availability	Cynomolgus monkeys	Male	Observations of agnostic behavior in group housing condition
	[96]	D2 receptor antagonist decreased rank of dominants	Japanese macaques: CD1 Mice	Male + Female: Male	Agnostic behavior observation, resource competition task (food priority test): tube test
	[97]	D1 receptor antagonist increased rank of intermediates	Japanese macaques: CD1 Mice	Male + Female: Male	Agnostic behavior observation, resource competition task (food priority test): tube test
	[100]	Altering D1 and D3 MSN activity altered rank, coping behaviors, and stress susceptibility	C57BL/6J Background Transgenic Mice	Male	Tube Test
Hypothalamic circuity in dominance and aggression	[104]	Rank dependent biological differences	Cichlid Fish	Male	Focal behavioral observations and morphological differences (eyebar and body coloration)
	[105]	Gene expression differences between ranks	Cichlid Fish	Male	Behavioral observations and morphological differences (eyebar and body coloration)
	[106]	Subordinates becoming dominant had immediate early gene activity in the hypothalamus	Cichlid Fish		Behavioral observations and morphological differences (eyebar and body coloration)
	[107]	Subordinates becoming dominant had reduced cortisol and down regulated CRF receptor expression	Cichlid Fish	Male	Behavioral observations and morphological differences (eyebar and body coloration)
	[108]	Dominants have larger somatostatin neurons in the hypothalamus		Male	Behavioral observations and morphological differences (eyebar and body coloration)
	[109]	Dominants have larger GnRH1 neurons within the hypothalamus	Cichlid Fish	Male	Behavioral observations and morphological differences (eyebar and body coloration)
	[110]		CD1 Mice	Male	Agnostic behavior observation in established group housing
	[111]	Subordinates have increased corticosterone. Genetic differences in hypothalamus between ranks.	CD1 Mice	Female	Agnostic behavior observation in established group housing
	[117]	inhibition of neurons in premammilary nucleus in dominants with activation in subordinates swapped ranks	C57BL/6J Mice and BALB/c Mice	Male	Hierarchy Corridor Test (Adaptation of tube test)
	[120]	Dominants had higher orexin gene expression	Zebrafish	Male	Agnostic and subordinate behavioral observation in home tank
	[121]	Starvation increased rank via orexin by increasing AMPA-type glutamate receptor activity	Transgenic and WT Zebrafish	Male	Agnostic behavior in newly combined dyads