Fear of any particular enemy is certainly an instinctive quality, as may be seen in nestling birds, though it is strengthened by experience, and by the sight of fear of the same enemy in other animals.
Etsaiaren beldur izatea, dudarik gabe, instintuzko koalitate bat da, habian dauden txorikumeetan ikus daitekeen moduan, gero esperientziak eta beste animaliengan etsai beraren beldurra ikusteak beldur hori areagotu egiten duen arren.