I'm partial to it, because I wrote it. But here's what Psychology Today had to say about it:
"[Gallagher] invites couples — newlywed, unwed, and otherwise — to reenact 50 recent social science studies that illustrate why relationships are so tricky and that reinforce the benefits of supporting each other in large and, especially, small ways. His summaries and takeaways make for a creative introduction to both research and commitment. Gallagher has made solid choices in the studies he presents, with easy-to-reproduce conditions that reinforce proven lessons on how to work together on budgeting, charity, travel, and division of household responsibilities, as well as generally being kind to each other."