The NEw York Times includes an op-ed on the emotional connections and personal fulfilment.
Stephanie Coontz writes (excerpt):
Instead, we should raise our expectations for, and commitment to, other relationships, especially since so many people now live so much of their lives outside marriage. Paradoxically, we can strengthen our marriages the most by not expecting them to be our sole refuge from the pressures of the modern work force. Instead we need to restructure both work and social life so we can reach out and build ties with others, including people who are single or divorced. That indeed would be a return to marital tradition — not the 1950s model, but the pre-20th-century model that has a much more enduring pedigree.