L6 - Agression Flashcards
Why does aggression usually occur?
Limited resources:
- mating opportunities
- obtaining food
- securing territory
- providing safety for family members
How has female dominance evolved into happening?
Mothers are forced to engage in competition to secure food for their young when they are incapable to do so
Where was the studying of female dominance pecking order first done?
Norway on chickens
What are the effects in the body during an aggressive reaction
Adrenaline and norepinephrine are released causing:
Increased blood sugar
Increased oxygen supply
Blood directed away from digestive and reproductive organs to the muscles, heart and brain
Describe how the HPA axis works
Hypothalamus –> Pituitary Gland –> Adrenal Gland
H: releases CRH (corticotrophin release hormone) which is a peptide hormone and NT that stimulates ACTH in response to stress
P: releases ACTH which is a polypeptide trophic hormone, causes the increased release of cortisol
A: releases cortisol which is a steroid hormone (glucocorticoid) from the zona fasciculate of the adrenal cortex in the adrenal gland.
What effect does cortisol have on the body?
It increases blood sugar through gluconeogenesis, supresses the immune system and helps the metabolism of fats, protein and carbohydrates
What effect does serotonin treatment have on aggression?
It increases aggression
What must an animal take into account if choosing a fight response over flight?
The value of the resource - may differ between individuals, hungry/not hungry etc
What is the Hawk-Dove game?
Hawks always escalate –> high injury risk, low time displaying
Doves threaten to escalate –> low injury risk, long time displaying
What is the winner/loser effect?
Winners keep winning and losers keep losing:
due to an increase in testosterone in winners and a decrease in losers
E.g.: older siblings beat their younger ones, even when younger ones grow larger at a later age
What is the bystander effect?
OBSERVING AN AGGRESIVE INTERACTION CAN HELP WITH LEARNING ABOUT OPPONANTS - RAISES TESTOSTERONE LEVELS
Give an example of animals that intervene with fights/protect others
Support of the preferred group member to protect social bonds in a herd
E.g.: female spotted hyena supports the dominant individual
What is the audience effect
Competing individuals change their behaviour if they are being watched
