If you have siblings, you get it. You understand what it's like to gaze adoringly at a favorite brother or sister and think, "At least there's one person on Earth who really understands me." Or, conversely, to look at a not-so-favorite sib and wonder, "Where in the world did this person come from? We might share DNA, but that's the only thing we have in common!" If you have siblings, you know just how complicated the bonds between us and our first housemates can be. So, maybe nothing in Jeffrey Kluger's fascinating book, The Sibling Effect: What the Bonds Among Brothers and Sisters Reveal About Us, will surprise you, but I guarantee it will make you think. Not to mention psychoanalyze every interaction you've ever had with your brothers and sisters.

Kluger's book began as a series of articles for Time magazine—where he works as both a writer and senior editor—then evolved into a much longer work about the complex relationships between sibings. Using his own experience of growing up in a tight band of brothers as a framework, he explores what happens between brothers and sisters as they are reared together in the same home. Kluger talks about the biological reasons siblings depend on each other and some of the variables (sibling rivalry, divorce, abusive parents, etc.) that can strengthen or destroy the bonds between them. He also brings up things like birth order (which he believes is interesting, though far from conclusive), favoritism (a natural phenomenon that can have devastating and long-lasting effects), the almost telepathic relationships between twins (fascinating, albeit a little eerie), and the psychology behind "lonely onlies" (who may not be as dysfunctional as some believe them to be). As Kluger touts the benefits of having siblings—who function as our first classmates, teachers, friends, and confidants—as well as the hardships—decreased parental attention, soul-stripping rivalries, etc.—he uses his own example to prove why sibling relationships matter, why they're worth preserving.

To the FTC, with love: Another library fine find