William Hamilton, an evolutionary biologist and described as one of the greatest evolutionary theorists of the 20th century, has devised a formular for altruism.
C < R x B
C is the cost in fitness to the actor, R the genetic relatedness between the actor and the recipient and B is the fitness benefit to the recipient.

This formular has been tested in a a study of a population of red squirels Home : Nature Communications : Nature Publishing Group
This formular known as Hamiltons rule was backed up by the study, where several orphaned squirels were adopted by kin.

My case is, because C is in the rule, can it really be classed as altruism, which is defined as a selfless concern for the welfare of others.