It is true that morality has, historically, been applied more consistently to the in group and discounted, at best, to the Other.

I think it's not that there are two moralities, but rather two realms. There was a time when interaction with other tribes was limited to trade, largely as a function of necessity, and when there were sufficient disputes around those relations, it led to war or famine or both. Interactions were limited, guarded, and often negative.

Today our relations with other "tribes" are more sophisticated in some ways, and hardly different in others. The impetus to tolerate more difference comes from the effective shrinking of the world via affordable, fast and easy travel and commerce and the instantaneous and nearly free communication facilitated by the Internet, and doubtless in the future, by the perspective of a spacefaring society. Old boundaries are becoming blurred, and we're having some challenges absorbing and adapting to that.

I believe there has been shown to be biological correlates to this idea. Emotional empathy creates in-group, out-group tribalism. Oxytocin, a hormone released when a newborn child nurses evokes emotional empathy. In contrast, cognitive empathy erases these between-group barriers and is evoked when we hear narratives about others that suggest our common humanity.

Leon Festinger, in his work on groups, noted that in cohesive groups governed by the sharing of a rather rigid set of beliefs and values act in a very controlling manner. People outside the group are treated as a lesser "other." Within the Group, if a member acts in a manner that violates the norms of the group, the group cajoles him gently, reminding him of the norms. If he or she continues to violate the norms, their pressure mounts and becomes more coercive. If the violation is viewed as major enough and if the violator does not conform, he or she will be expelled from the group and treated as a lesser, untrustworthy heretic.

Of course, this most true in groups dominated by adherence to strict dogma -- social, religious, political, or economic.

I see truth in that statement. I see it all the time, with others and recognize it myself.

Morality like everything else here has variations on a theme. There is no absolute.

"Morality" is wholly subjective.

My experience as a JW was like this: first the interested person was love-bombed with expressions of love and idealism. When you were officially in, then the apologetics began for why it wasn't as loving and idealistic as it was made out to be. The people in the group were 'brothers and sisters' and the outsiders were 'worldly people'.