A correlation has been found between the size of of a fish known as the “desert goby” and its level of aggression.
The male cares for the eggs once they are laid by aggressively defending it against intruders. Research has found the smaller the male the more aggressive it is in nature.
This has been attributed to a case of “napoleon complex”, the notion that it is over-compensating in an attempt to fend off larger marine life.
They were found to attack sooner and with more intensity, to avoid revealing physical inferiority to intruders.
Read more at Monash University