Why Do So Many Single Dudes Sleep on Just One Pillow?

Why do so many single men sleep on a single ratty pillow? Psychologist Steven Richards tells VICE that the desire to snooze uncomfortably is rooted in males' caveman biology. "It means that men don’t get too comfortable, in case they have to wake up suddenly and defend the 'cave' against predators, or even other men," says Richards. "The worn-out pillow, being probably on the unclean side, will enhance immunity. So even that has survival value, in the context of male 'warrior' instincts." My big question then is...what about married men? If they like more than one pillow are they neglecting the cave? More importantly, why didn't the psychologist answer why women enjoy SO MANY pillows? Are we stuffing the cave? lol!