The topic has circled families since the birth of the very first set of siblings.
Conventional wisdom jokes that the first-born often gets the most attention; the most pictures in the family album and the most time with parents.
Now, a new Brigham Young University study gives credence to the myth. The study says first-born children, between the ages of four and 13, get 30 percent more quality time with their parents than younger siblings.
In real time that's about 3,000 additional hours, which defined quality time as minutes spent together over homework, meals, reading, play time, sports, and conversations.
"All eyes are on the first-borns," said Kevin Leman, author of "The Birth Order."
Trying to balance time equally among children is a problem over which many parents agonize.
"Each of them is my favorite at some point during the day," said Jolene Ivey, a mother of five boys.
Ivey said her boys still compete for her attention.
"It's not like they're here all the time or not enough. So it's good right now," said Ivey, whose children range in age from eight to 18. "The time is divided good."
But even her oldest son, 18-year-old Alex, said he recognized the difference between the time he and his parents spent together growing up versus the amount his younger siblings received.
"They would be able to read me a storybook before I went to sleep, but that doesn't really happen with my little brothers anymore," said the Columbia University freshman.
According to some child psychologists, there is a reason for all the extra attention — and no, it's not because the first-born is a parent's favorite or first love.
"We devote all this time to the firstborn. Then, when other pups come along, it splits up the pie and everyone has to share," Leman said.
Ivey agreed with the sentiment.
"Each child, instead of getting 100 percent of 100 gets a little less of that pie," the 46-year-old said.
All that extra time first-borns receive often means extra pressure on them to succeed.
"First-borns get a lot of encouragement, a lot of attention and great expectations that, 'Hey, I expect you to achieve,'" Leman said.
For the Iveys, the expectations go beyond Alex.
"We have high expectations for Alex, but we have high expectations for all of them," Ivey said.