All these manifestations of symbolic »minimal clothing« such as the lumbar cord, the tied up penis, the penis sheath or the namba, which seems to accentuate the penis, are based on a common meaning: All these practices follow, but also demonstrate, the norms of shame and behaviour applicable in the respective societies, that the power of the male sexuality of their wearers is restrained and under control, so that they fit into the social rules of the community and the wearers of these items do not pose a risk of attacking others.
The utensils are therefore not just »covering« garments, that shall protect against the looks of others, but symbols of acceptance of the valid social rules and norms. This also makes it understandable, that the one, who looses these symbols, is ashamed: He is thus outside his social community and is anxious to fit back into it!
So this is not just a matter of a body-related »shame of being naked« or a »genital shame«, but the much more important and complex »social shame«, ie the endeavour to fulfil the consensus of human coexistence in the respective social community. There are two very important reasons, why this »social shame« plaid and still plays a central role in human development:
First, a successful, peaceful coexistence in a social society is only possible, if all members quite certainly refrain from attacks and therefore abide by regarding social norms. The observance of such social norms is vital for the human society
Second, the individual was incapaciously doomed to downfall, if leaving the social community or was expelled from due to a breach of a norm – much more so in the past, than today.