Say it ain't so! A study found that parents may, in fact, favor one child over another.

A few nights ago, as I was putting my son to bed, he looked up at me with his big brown eyes and asked, "Do you think some parents like one of their kids better than the others?"

The question caught me off guard. Not because I hadn't thought about it before, but because I had. I am 47 years old, and even today, It's still a running joke between my mom and I that my brother was her favorite. She can deny it all she wants (and she does), but it's just something I've always...felt.

Turns out, I'm probably not the only one. According to a recently resurfaced study, having a parent who plays favorites is not the exception, but pretty much the rule. Researchers followed 384 families in which a pair of siblings was born within four years of each other, and found that 74 percent of mothers and 70 percent of fathers reported preferential treatment toward one child.

Wow!

I'd be doing a major "I told you so" dance and forwarding this study to my mom right now if not for one small thing. I am a first-born. And while the research found that playing favorites definitely affected younger siblings' sense of self-worth, the differential treatment didn't really seem to affect first-borns. In fact, the first-borns actually reported feeling they were the preferred child more often than not.

Hmmm.

"I was a little surprised by that," lead researcher Katherine Conger told Quartz. "Our working hypothesis was that older, earlier born children would be more affected by perceptions of differential treatment due to their status as older child—more power due to age and size, more time with parents—in the family."

Makes sense, I guess. But meanwhile, my son is a second-born. So as I kissed him goodnight, I assured him that his daddy and I love both him and his sister the same. "I know that, Mommy," he said. "I really, really know that."

Phew.

Look, we all love all of our children equally. And because of the bias I felt growing up, I try even harder to always play fair. But it's hard not to waver from time to time. Kids have different personalities, different strengths, different weaknesses. And so do we, as parents. Which means one day I may click better with one of my kids, then the next day it will be the other.

So am I surprised that the study also revealed that no matter when a child is born, every single one of them thinks their parents dig another sibling more? Not really. "Everyone feels their brother or sister is getting a better deal," Conger said.

Which means that no matter what you do, it's basically a lose-lose situation for all us parents today, so don't stress it.

As for my issues with my own mother...I may still give her a hard time about it on occasion, but I've long since made peace with it.

I was my dad's favorite, after all.