"For mankind, it is not survival of the fittest, it is survival of the cruellest." Has this been your interpretation after reading King Lear?.
The characters Gonerill, Regan and Edmund could be categorised as the cruelest in Shakespeare's play, King Lear. Gonerill, Regan and Edmund's deception to their friends and family is ultimately for their own gain and survival. The end of King Lear however, sees Gonerill, Regan and Edmund all dead. Cruelty most certainly aided in their rise to power, Edmund's rising to the Earl of Gloucester and the daughters" acquisition of their Father's land proves this. All the characters that were considered evil did die, however many of those that were kind died as well. Cruelty most definitely played a role in the character's survival, however was not the sole reason for this. It would still be accurate though, to state, that in King Lear it is not survival of the fittest, it is survival of the cruelest.
Gonerill and Regan make the first cruel deception. Both sisters lie to their father, the goal that was to be achieved from this was to acquire his land. After succeeding, the daughters neglect their father and treat him with extreme disrespect. In being cruel towards their father they are protecting themselves, as not to allow his soldiers to create havoc in their castle. Similarly Edmund deceives his family, both his brother and father. Edmund most cruelly informs Gloucester of Edgar's plans to overthrow Gloucester and gain the throw. The information given to Gloucester is entirely fictional and is a plot by Edmund to be rid of both his father and his brother. These cruel acts of treachery are performed so Edmund can rise in power and gain access to his father's thrown. .
Edmund, Gonerill and Regan's cruelty is horrifically shown in the decision they make for their own survival and uprising. Edmund, in order to be rid of his father Gloucester, lies to Regan and Cornwall and informs them that his father is conspiring with France.