Anyone with more than one child has heard, “You don’t love me as much as my sister,” or something very much like it. And I’m guessing that most of us have responded with shock and answered, “Of course not, kiddo, I love all of you exactly the same.” I even went so far as to tell my then-youngest, who insisted that there wasn’t enough love to go around, a metaphorical story about a candle. “The flame is my love for your sister,” I explained–very proud of myself for was was going to be the definitive brilliant response.

“Now, here’s another candle–that’s you. See how we can light it from the first one and we end up with twice as many flames? That’s how love is. It can grow and grow without taking anything away from anyone else.” I thought that explanation was pretty good, but deep down I knew my daughter was right. Not that I loved her sister more, but that I didn’t love them the same way. I always felt a little guilty about my little secret, but it turns out that I’m not the only one.  And chances are, you’re right there with me.

“It is my belief that 95 per cent of the parents in the world have a favourite child, and the other five per cent are lying,” writes Jeffrey Kluger, author of The Sibling Effect: What the Bonds Among Brothers and Sisters Reveal About Us.

Researcher Catherine Conger at the University of California, Davis, did a three-year study of 384 families with two or more children.  She watched how the parents worked through conflicts with the kids and found that 65% of mothers and 70% of fathers had a clear preference for one of their children. Conger felt that her numbers were low since all of us try to be on our best behavior when we’re being watched.

The preference, by the way, was usually for the older sibling, which is what a lot of other research has shown.  While I do agree that we love our kids differently, I question one of the behaviors that supposedly proves the point. Looking through my photo albums, I’ve got probably 20 times more pictures of my oldest than the next youngest, who’s in 20 times more pictures than my third one. I think that’s more of a function of time than preference. When you have two kids running around in different directions, it’s a lot harder to set up cute photo ops. Add a third or fourth and it’s amazing anyone has any pictures at all.

If you’re interested in exploring this more, there’s a fascinating article in the British Newspaper, The Telegraph.