In many ways we have the social strategy of an armadillo. Each of us walks around in his own individual shell, allowing only slender peeks at his inner softness. The tough crust protects us from our competitors in much the same way the armadillo's shell wards off enemies who would destroy those tender inner parts. We take our opaqueness so much for granted that the small patch of inner skin which we customarily bare to dose associates becomes magnified in our own mind as self-disclosure. How much we expose ourselves socially is metered by our experience, but the machinery and the parameters were given to us by our distant ancestors.
Social strategies are a big part of the evolution of behavior.
How one approached an unknown social situation has surely been one of the fundamental determinants of how many genes he contributed to following generations. By necessity , one must operate differently toward family members, peers, subordinates, neighbors, and enemies. Among the exceedingly complex characters of these relationships, perhaps the main element is how much of his inner self one discloses or conceals. One has a spectrum of aligned strategies stretching between personal transparency and complete obscurity. Opening up to others is the main element in the social bond in all its forms.