Humans are pair bonders who face costs when experiencing separation or isolation from close, trusted companions. Another reason to find ways to increase relationship harmony is to forestall the adverse effects of isolation or separation.
Association of loneliness with all-cause mortality: A meta-analysis
Loneliness and social isolation as risk factors for mortality: a meta-analytic review
The emotional cost of poor mating performance
Determinants of female sexual orgasms (more masturbation has not made women more orgasmic)
Growing Desire or Growing Apart? Consequences of Personal Self-Expansion for Romantic Passion