Olivia Laing contemplates the meaning of loneliness in a piece for Aeon Magazine:
Something funny happens to people who are lonely. The lonelier they get, the less adept they become at navigating social currents. Loneliness grows around them, like mould or fur, a prophylactic that inhibits contact, no matter how badly contact is desired. Loneliness is accretive, extending and perpetuating itself. Once it becomes impacted, it isn’t easy to dislodge. When I think of its advance, an anchoress’s cell comes to mind, as does the exoskeleton of a gastropod.
I think Olivia is correct in hypothesizing that loneliness comes and goes in vicious cycles (it’s hard to break free when you’re in a slump).
It seems that this is what loneliness is designed to do: to provoke the restoration of social bonds. Like pain itself, it exists to alert the organism to a state of untenability, to prompt a change in circumstance. We are social animals, the theory goes, and so isolation is — or was, at some unspecified point in our evolutionary journey — unsafe for us. This theory neatly explains the physical consequences of loneliness, which ally to a heightened sense of threat, but I can’t help feeling it doesn’t capture the entirety of loneliness as a state.