As part of the celebration for National Siblings Day, I chose to resurface The Sibling Effect this week—a book written several years ago about the impact that birth order and our siblings have on our personalities and trajectory.

Reading this book, you may not agree with some of the theories inside or you may feel a bit uncomfortable at just how accurately they describe your relationships (either past or present) with your own siblings. Regardless, there is plenty of research today about the science of siblings and what role that plays in our own development. Similarly, this research delves into what impact this has when someone grows up with no siblings or loses a sibling. So today, in honor of National Siblings Day … The Sibling Effect is my pick for the Non-Obvious Book of the Week.