So in a complex technologically advanced civilization where the individual no longer needs relationships to reach great well-being, could enough random mutations cause the desire for relationships as well as sexual lust? Even if they still desire others and this was apart of reaching great well-being it would come down to how they reproduced.
This is to say though that enough of the population reproduced without another person present to result in a significant portion of people with the mutations. I could see how many people might even prefer this so that they could cherry-pick desirable genes. This ambition for perfect genes mixing with contraception perhaps could make it more realistic.