Relationships are neccesary for a society to function properly and orderly due to the fact that people have a natural desire to interact with others.
Not neccesarily interactions with people but any interactions whether with inanimate objects like Tom Hanks in Cast Away, or examples of animal hoarding, and then “normal” interactions.
In certain studies people have been known to go certifiably insane without interaction of any kind for long periods of time, an example would be a person in prison placed into solitary confinement.
Normal interactions would consist of talking to people with normal social skills and learning what to say and what not to say at certain intervals.
This is an example of learning what is morally right or wrong in society to either discuss whats happening in the world. Also learning normal social skills versus being left alone with nobody to interact with you will go into a withdrawl and will go insane over a certain time period.