Winner and loser effects
[2] The outcomes of winner and loser effects help develop and structure hierarchies in nature and is used to support the game theory model of aggression.
[3] A theory underlying the causation of the winner and loser effect deals with an animals perception on its own and other members resource holding potential.
[4][5][6] Essentially if an animal perceives that it has a high resource holding potential then it considers itself to be a dominant member of an intraspecific community.
[4][5] Animals, regardless of size, with a higher perception of resource holding potential are more likely to initiate aggressive behaviour to maintain their dominance within a community.
[2] The reason an animal will accept its dominant or submissive position in a hierarchy is because of the game theory model of aggression.
Game theory discusses a frequency-dependent model where both traits (aggressive vs submissive) can exist when the frequency of each meets an evolutionary stable strategy (ESS).
[2] In some animals winner and loser effects have been shown to cause hormonal differences in blood plasma.
[2] Corticosterone is a stress hormone and is likely raised due to the implications of a loss in animals experiencing the loser effect.
[7] It also showed in a group setting that the team member who was the top-scoring player or did the most work received the highest boost in testosterone.
[7] Winner and loser effects are driven by an organism's previous experiences, typically in an aggressive context.
[8] The literature also showed that encounters that happened two times before an aggressive event can affect the strength of the winner or loser effect.
[9] Neutral individuals who have little to no experience with aggression interactions fall in an intermediate position between winners and losers forming the Winner-Neutral-Loser (W-N-L) hierarchy.
Male copperhead snakes, who have not had an aggressive interaction in months, when put in a situation to fight for a female is likely to win an encounter on the basis that his body size is larger than that of the other fighter.
[10] This indicated that previous experience in winners does not increase their ability to reproduce as they are just as likely to lose a fight if a snake of a larger size challenges them.
