One Reads, The Other Runs: Identical Twins And Sports

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Only A Game's Bob Shaffer (left) never thought sports was his thing. Instead, that was his twin brother Bill's specialty. But aren't identical twins supposed to be identical? (Karen Given/Only A Game)
Only A Game's Bob Shaffer (left) never thought sports was his thing -- that was his twin brother Bill's specialty. But aren't identical twins supposed to be identical? (Karen Given/Only A Game)

I’m 8 years old and I’m watching my identical twin brother play first base.

It’s hot and humid, and bees are buzzing around the trash can next to me. I only hear the bees... I’m not watching them or the baseball game.

I just got to the part where Harry finds out the truth about Sirius Black.

'Am I A Bad Identical Twin?'

"I remember that you would sometimes bring a book to my baseball games," my identical twin, Bill, says. "I do vaguely remember seeing you on the stands with a book."

My mom didn’t quite know what to make of us.

"I did worry and I, as a mother, always wondered if you were truly happy sitting there reading your book," she says. "Because you certainly didn't look excited."

Bill and I have always had our simple go-to answers for when people ask how “different” we are. Bill plays the drums and thinks Iron Man is the best. I play the saxophone and know that Batman is better.

But these small differences were all conscious choices we made as we grew up.

When it came to sports, Bill was always naturally talented — I was not.

On the rare occasions I would get out on the field, we’d be on the same teams with the same coaches — and Bill would still be better.

What gives? Aren’t we supposed to be identical?

Is this normal or am I a bad identical twin?

Sports Ability In Twins

"No, you're certainly not a bad identical twin at all," said California State University Fullerton's Nancy Segal.

She was just being polite, because her research seems to suggest that Bill and I shouldn’t be as different athletically as we appear to be.

Segal is a professor of developmental psychology and is also the founder and director of the Twin Studies Center. She says that compared to fraternals, identical twins are much more alike when it comes to the physical attributes that determine sports ability — things like muscle fibers and how much oxygen your body takes in.

And, actually, Segal says the athletic similarities seem to go beyond just physical traits.

"What strikes me about other identical twins I’ve seen on sports fields is that they really have an uncanny knowledge of what the other one is about to do or what the other one is about to think," she said.

Robin Lopez, #8, formerly with the New York Knicks, says his brother Brook and he purposefully developed opposite skills so they could play at the same time. Brook plays for the Brooklyn Nets. (Elsa/Getty Images)
Robin Lopez, formerly with the New York Knicks, says he and his twin brother Brook purposefully developed complementary skills. (Elsa/Getty Images)

So, identical twins are practically matched down to the muscle fiber — and they’re also supposed to think the same way on the field.

If these things are true, then why was I reading Harry Potter instead of playing sports? I thought a pro might have some answers.

The NBA's Robin Lopez Weighs In

Robin Lopez is a center for the Chicago Bulls. And he’s an identical twin. His brother Brook is also a center in the NBA — he plays for the Brooklyn Nets.

Seven-foot identical twin brothers playing in the NBA? I didn’t have a ton of hope that Robin would make me feel better about my situation. But, I needed to know...

"When it comes to basketball, is there anything that you can do that he can’t?" I asked.

"I think there are a lot of things," Robin said. "I think I'm better than him defensively, maybe rebounding. But particularly offensively, he's a better scorer, better shooter, more of a threat to go to work on the block, wider array of offensive moves."

So while Robin and Brook Lopez are talented enough to play in the NBA, they are good at different things.

Maybe, I thought, I’m not such an unusual identical twin after all.

But why are Robin and Brook so different?

"Well, I think it's that we both wanted to share the court," Robin said. "We wanted to be able to play together at the same time, so our games are very complementary in that sense."

In other words, Brook and Robin weren’t born with these athletic differences, they created them.

Bill and I never tried to be athletically different. We just always were — it’s been like that since kindergarten.

A Possible Explanation

Twin researcher Nancy Segal had a possible explanation.

"Identical twins are not strictly identical," Segal said. "The reason for that is a lot of events can happen after the fertilized egg is formed that will make identical twins differ. For example, there can be individual mutations in one twin, not the other. I'm actually surprised identical twins are as alike as they are behaviorally and physically given all the many influences that can work to make them different."

This was big. I always assumed identical meant "identical."

Now I had a possible explanation for my athletic deficiencies: I’m clearly a mutant twin! My genes just have more mutations than Bill’s and that’s what’s causing our athletic differences.

So I thought I'd dig a little deeper into this idea.

Slings And Arrows

"No, I don't think that you're weird," said Hermine Maes, an associate professor at Virginia Commonwealth University and the Virginia Institute for Psychiatric and Behavioral Genetics.

Maes explained that while identical twins can have genetic mutations, they still tend to be much more genetically similar than not.

Now with the Chicago Bulls, seven-foot center Robin Lopez attended Stanford University and played for the New York Knicks during 2015 -- his identical twin brother also attended Stanford and plays for the Brooklyn Nets. (Andy Lyons/Getty Images)
Now with the Chicago Bulls, seven-foot center Robin Lopez attended Stanford University. His identical twin also attended Stanford, and plays for the Brooklyn Nets. (Andy Lyons/Getty Images)

In fact, Maes says those mutations barely make a difference when it comes to athleticism.

What does make a difference? Forces from the outside environment.

"These are just the sort of slings and arrows of outrageous fortune," Maes said. "Certain things happen to you that influence you, but only you, and the same with your brother."

When she says slings and arrows, think differences in training. Maes believes that any perceived athletic difference between Bill and me is a result of the time he spent on the field while I was reading.

But, I wasn’t reading Harry Potter in kindergarten, and Bill has always been better than me at sports.

"If we were to compete against one another would there be differences there? Is that what you would expect?" I asked Maes.

"Not necessarily," she said. "It would be interesting to study anyway, but, likely on certain aspects that are sort of more basic underlying factors that determine whether or not you’re good at sports, I would expect that you probably aren't all that different."

In other words, if we tested more basic skills like sprinting or jumping — instead of specifics like shooting foul shots — Maes would expect us to be even.

This was still hard for me to accept.

The Twin Pentathlon

So, on one of the hottest days of the year, producers Karen Given, Martin Kessler, intern Ian Foster and I decided we needed to put Maes’ theory to the test. If Bill and I faced off in tests of natural athleticism, would we see real differences? Or, as Maes suggested, would we be practically the same?

First up was a 75-yard dash which, to everyone’s shock, I won!

After sprinting came 75 yards of running backwards — that was tough. Bill took that one. And, honestly, I’m glad. Who wants to brag that they can run backwards really well?

So we were tied 1-1 with three events to go.

Next up was the long jump. Again, Bill won. The pentathlon was starting to go sideways, just like I knew it would.

But Karen and Martin had found a test for balance on the Internet, and that's an innate skill. It was a little complicated, but somehow I ended up winning!

At that point, Bill and I were exhausted and the contest was all tied up... again.

"It’s almost like you guys have similar genes," Martin said.

Bob (left) and Bill (right) go head to head -- or arm to arm. (Karen Given/Only A Game)

And he had a really good point. Was that actually the answer?

We had one more event to go: arm wrestling, best of three. Bill ended up winning. To my surprise, arm wrestling took a really long time. In one round, our arms didn’t budge for almost 30 seconds.

So in the end, Bill won the Twin Pentathlon — but only 3-2.

I was honestly shocked. Years of belief were shattered, and I can confidently say that Bill is no longer the more athletically-gifted twin. He might be slightly more skilled, but I’m certainly not unathletic, like I always thought I was.

And I’m definitely not a bad or abnormal identical twin when it comes to athletics, which is good to know.

Maybe I should have started caring about sports when I was a kid. I mean, I could’ve at least played Quidditch.

This segment aired on August 6, 2016.


Headshot of Bob Shaffer

Bob Shaffer Producer
Bob Shaffer was a producer in WBUR’s newscast unit.



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