Sometimes the deck really can seem stacked.

Kids with last names that start early in the alphabet tend to be more likely to receive tenure at a top department. Kids with easy to pronounce names tend to be judged more positively than people with names more difficult to pronounce. Girls with masculine-sounding names are more likely to grow up to have successful legal careers.

Then there's the birth-month effect: As Malcolm Gladwell writes in OutliersCanadian kids born in January, February, or March are much more likely than those born in later months to become elite hockey players. Since youth hockey teams are grouped by age, kids born early in the year tend to be bigger, stronger, and faster. 

Malcolm calls it an "iron law of Canadian hockey" (although some are skeptical of the correlation, much less causation.)

Here's another example of the birth-month effect: Research shows the number of CEOs of S&P 500 companies born in June and July is disproportionately small compared to those born in other months.

Out of 375 CEOs studied, 23 were born in June and 22 in July.

The average number for the other ten months of the year? 33.

U.S. schools admission cutoff dates typically fall between September 1st and January 1st, making children born in the summer months of June, July and August the youngest in their class. However, to the extent that parents hold back their children born just before the cutoff dates due to their relative immaturity and possible parent awareness of the relative-age effect... children born in August may be among the oldest.

For this reason, it is the children born in June and July who are likely to be the youngest among their classmates and... have a significantly lower chance of becoming a CEO than those born in other months.

Why? For one thing, research shows that relatively oldest students are 11 percent more likely to be high school leaders. Other research shows students who acquired leadership skills during high school are more likely to be in management roles a decade later.

But common sense also applies: Kids who are eight to ten months older than their peers in a second-grade classroom are likely to have a leg up in terms of intelligence and maturity.

When you're twenty years old, those "extra" months are irrelevant.... but when you're eight, those extra months might make a real difference.

There is mounting empirical evidence that children born right before the school admission date are at a disadvantage as a result of being up to a year younger and less physically and intellectually developed than classmates in their school grade.

As a result, these children are selected for fewer leadership roles in school activities in their beginning school years... children born in the months right before the cutoff date of school admission are less likely to be a sports team captain or be chosen for a speaking part in school plays.

This well-documented condition has become known as the ''relative-age effect'' or the "birth-date effect."

What does all this mean to you?

One, find ways for your kids to gain leadership skills, especially if they're among the youngest in their class. Help them learn to take initiative. Help them learn to volunteer. Encourage them to step forward when others step back.

Because that's what leaders do -- regardless of their job title.

And always remember that while some cards will always be stacked against us... what we do with the cards we're dealt is what matters most.