The more victories someone notches up in fights, the more aggressive they become - and the same is even true for crickets, say researchers.
Scientists from the University of Leipzig in Germany staged cricket ‘tournaments’ and found that the winners became increasingly wound up as they progressed.
The study investigated the source of the heightened aggression, dubbed the ‘winner effect’, and discovered that increased levels of adrenalin were responsible.
Hard-hitting facts: The more fights you win, the more aggressive you become
The researchers, led by Paul Stevenson, studied 958 crickets in total and found that the winner effect is actually temporary with the aggression levels returning to normal around 20 minutes after the fight.
They also found that treating the crickets with a chemical called epinastine, which interferes with the invertebrate equivalent of the adrenaline pathway, abolished the winner effect, suggesting that adrenaline flow is involved in aggression increase.
The researchers didn’t insist on the Queensbury Rules, but did match the crickets by weight and by experience.
Study: In total 958 crickets took part in the 'tournament'
Adrenaline is a naturally produced hormone that is produced in stressful or exciting situations.
The main physical effects are an increased heart rate, contracted blood vessels and the expanding of air passages.
The results of the study were published in the online journal PLos ONE.