may play a role in establishing social hierarchy. A study that investigated the role of social construction and AVT compared territorial and non-territorial species of tropical coral reef fish. Experimenters administered Manning compound, an AVT agonist to the fish and found that, after treatment, non-territorial species displayed more territorial behavior whereas territorial species displayed less territorial behavior. Research suggests that the effects of AVT on aggression may be influenced by the social construction of the species. For example, in a study done with Rainbow Trout, increased levels of AVT were associated with more subordinate behavior. It is currently hypothesized that the contrasting effects of AVT are related to the distinction between territorial versus colonial social systems. In a territorial species, such as Rainbow Trout, AVT is linked to less dominant behavior. This may be due to the differences in the distribution of AVT receptors in territorial and colonial species. Sources External links Neuropeptides Oxytocin receptor agonists Vasopressin receptor agonists