unfortunately you cannot only work with what's here is wiki.  and i cannot expect you to be a specialist:  the sentence "that alleles can become fixed or spread in a population because of the benefits they bestow on groups, regardless of the fitness of individuals within that group" should give you a hint if you compare that to the first sentence in "kin selection".  you should read eliott's sober's book "the nature of selection" if you really care about this. it gives the proof that "kin-selection" is a case of group selection