The Chemistry of Love.
If you can, I suggest not just reading the transcript of the interview but also listening, because there were some pretty interesting inflections that just don't come across in the printed world.
Of course, it is pretty annoying to me when I see the spin that has been put on the biological evidence that she has found. To a Darwinian evolutionist, biological pressures are the only reason for the phenomena that she describes. I would love to get a chance to look at the raw data from her experiments and compare it to some of the work done in the 1950s by Niles Newton (who did absolutely pioneering research on the influence of oxytocin on both pair bonding and parent-child bonding).
It is pretty obvious to me that romantic love, erotic love, and long term attachment all have a part to play in human marriage and family. I find it awe-inspiring to see just how well designed the ebb and flow of hormones is to create and maintain the bond between the marriage partners and to sustain them in their ability to care for their children.
I also find it less than co-incidental that this research is being publicized about the time of the release of Deus Caritas Est (which I still have yet to read).
You can also hear Deus Caritas Est at The Internet Archives (in case you don't have time to read it...).