It's consistent with the facts. These people have trained together for long periods of time and have already formed strong relationships, and they have much in common as far as temperament and personailty due to their educations and interests. They're young, fit, attractive, and as Type A personalities would love the opportunity to add another "first in space" to their personal, private resumes. More power to them. And as for "lack of privacy", well, a spacecraft is no more crowded than a yacht...

But on long missions, this could prove deadly. Love triangles, break-ups, crushes and stalking, unrequited love, jealousy, all take on a new meaning in deep space in crowded quarters. Love in the workplace and affairs between subordinate and command are minefields. And it's not like we can count on psychological screening to catch all the potential problems. We already have perfectly good evidence that competent astronauts can fall apart due to affairs of the heart right here on earth.