Samneric (Sam and Eric) represent totally civilized and socialized persons. As identical twins, they have always been a group, albeit the smallest of groups, but a group nevertheless. They know no other way than to submit to the collective identity and will. They are initially devoted to rescue but easily overwhelmed by the ferocity of tribe. They represent the well-intentioned members of general public who play by the rules of whoever is in charge. They are easily intimidated by Jack and abandon their fire-tending duties at his command. Seeing Ralph's rage at the resultant loss of a rescue opportunity, Samneric mock him once they are alone, despite the fact that their desertion of duty caused his anger and the loss of possible rescue. On a realistic, perhaps human, level, they may laugh to dispel their guilt or because their childish perspective has already allowed them to forget the loss they caused or because their priority is merely to avoid punishment. On the symbolic level, however, laughter is a totally social act.
After the horror of Simon's death, in which they participate, they fear for their own lives because they have remained loyal to Ralph. As Ralph's group plans to approach Jack's tribe, Samneric want to paint themselves like tribe members, hoping for mercy through assimilation. When the twins are captured by the tribe, Samneric "protested out of the heart of civilization" but abandon their loyalty to that civilization to avoid punishment, betraying Ralph out of concern for their own welfare. Their return to civilization will be fairly easy because they look only to appease whoever is in charge.