The notion of the American Dream is that anyone can work hard and be successful, and that those who achieve great things got to where they are through their dedication, brilliance and effort.

In “Outliers” author Malcolm Gladwell says those things are all well and good, but if you look hard enough there are almost arbitrary advantages that make a huge difference in who rises to the top.

“It makes a difference where and when we grew up,” Gladwell writes. “The culture we belong to and the legacies passed down by our forebears shape the patterns of our achievement in ways we cannot begin to imagine.”

I heard about this book long before I read it, specifically the example of elite hockey players. Gladwell says that if you look at any collection of people from this group, you’ll see that 40 percent of them were born in January, February and March. That compares to just 30 percent for July through December.

Why? It has to do with a seemingly innocuous decision — the date that youth leagues use as a cutoff to decide how old you are for that season. They say however old you are on January 1, that’s your age. So kids with January 2 birthdays end up being almost a year older than kids in the same league who were born December 31. That matters. They’re bigger, they’ve probably been playing longer, so they seem a little better. They end up being picked for all-star teams, which play more games and practice more, thus turning any small advantage in skill into a huge one, all because of that date.

I was a huge beneficiary of this growing up. I played baseball, and in our league the cutoff date was July 31. My birthday is August 3, so I was always one of the older kids. Gladwell says if you look at professional baseball players, more of them are born in August than any other month. Not sure where I went wrong.

But if you’re not that interested in sports, he says “these exact same biases also show up in areas of much more consequence, like education.” Parents have to decide when to start their kids in school, which makes a big difference given the group they progress with. Here, I was on the opposite side of things, always one of the youngest people in my class. I was in the same grade as roommates CA and MR as we went through school, but both of them are almost a year older than I am. Sure, everyone could drive before I could, but that didn’t mean I couldn’t do better than them on a test.

As part of a larger point, Gladwell brought up something about IQ that I thought was one of the more interesting notes in the whole book. He writes that experts say after a certain point, having a higher IQ makes no real-world difference. There are thresholds at which you are considered to have the mental capacity to pass high school or get through college, but he says someone with an IQ of 130 is no more likely to win a Nobel Prize than someone whose IQ is 180. He compares it to basketball players — if you’re 5-foot-5 there’s little chance you’re going to play in the NBA. But being 6-4 versus being 6-6 isn’t as big of a deal — you just have to be “tall enough.”

Being 6-3 did not help my basketball career, though if any NBA teams are reading, I am still a free agent.

Among other people, Gladwell writes about Bill Gates and how going to a certain high school that happened to have a really advanced computer, and then living near a college with a computer lab he could go to in the middle of the night were small advantages that led to his incredible success. These examples are interesting and make you think about how those little things add up. But Gladwell also takes moments here and there to give a more practical view of why we should pay attention to these things:

“Our world only allowed one thirteen-year-old unlimited access to a time-sharing terminal in 1968. If a million teenagers had been given the same opportunity, how many more Microsofts would we have today? To build a better world we need to replace the patchwork of lucky breaks and arbitrary advantages that today determine success — the fortunate birth dates and the happy accidents of history — with a society that provides opportunities for all.”

Amen.