JUDY WOODRUFF: Next, in case you’re been asleep, this is Super Bowl weekend. The heavily favored Carolina Panthers will face off against the Denver Broncos on Sunday for football’s biggest prize.

Hari Sreenivasan has our story.

HARI SREENIVASAN: A TV audience of well over 100 million is expected to tune in to see the Carolina Panthers quarterback Cam Newton go head-to-head with sentimental favorite Peyton Manning leading the Denver Broncos.

Both teams spent this week in preparations. The game caps a season of big rivalries, bigger setbacks and some surprise comebacks.

In a new book, “This Is Your Brain on Sports,” “Sports Illustrated”‘s executive editor, Jon Wertheim, along with co-author Sam Sommers of Tufts University, explore the psychology and behavior of sports teams and their fans.

For a closer look, Jon Wertheim joins me now.

So, “This Is Your Brain on Sports,” why the book?

JON WERTHEIM, Co-Author, “This Is Your Brain on Sports”: We all love sports.

There is so much that goes on in sports, it seems irrational or counterintuitive. And we dismiss that these are just sort of — these are the rules of the road of sports. And we wanted to dig a little and say, what really explains — what are the underpinnings, everything from the crazy T-shirt cannon that we go crazy about, to the fact that teams seem to elevate when there’s a rivalry?

What is really going on here? What is the human behavior? What is the psychology? What is going on here?

HARI SREENIVASAN: Let’s talk a little bit about rivalries.

The likelihood is that this might be one of Peyton Manning’s last days. So, it’s not a Peyton vs. Cam rivalry. But, sometimes, when two teams get together at the Super Bowl, it’s a much bigger deal for entire cities and fans. Why is that?

JON WERTHEIM: Rivalry is one of these essential elements of sports.

And what the research says is that there really is a difference in performance a run-of-the-mill game vs. a rivalry team. Physiologically, athletes in a rivalry game, testosterone levels are different. Saliva levels are different. These scores tend to be closer.

And this is true in life too. There are all sorts of studies. You put kids alone to take the SAT and then you put them in a room with other kids, and they will score better when there are other kids in the room.

When we bid on eBay, if it’s just us, we bid one way. If we have a rival, it may only be a code name, an eBay sign-in name, our bidding patterns change. So, rivalry really does — it’s sort of hyper-competition that really changes performance.

HARI SREENIVASAN: One of the elements of pressure that a lot of people don’t think about during the Super Bowl is the pressure that is on the coaches on the sidelines. And you kind of point out that the Denver coach is a relatively new one. The one before that Denver coach was a pretty darn good one, too.

JON WERTHEIM: In the NFL, especially, Hari, you have this monstrous turnover. About three years is the average tenure for a coach. Remember, they’re only playing 16 games, so not a lot of data points.

Ron Rivera, Carolina coach, five years, that puts him the top quartile for longevity. And we say, why is this? Why is there this turnover of coaches? And what we think is at play is the action bias, that the owners, your team is 8-8, and the fans are saying make a change, you’re 9-7.

And the owners say, you know what? We have got to do something. We have got to make it look like we care. And, again, this is human behavior. We do this all the time. This is why we’re too quick to buy and sell stocks. This is why physicians sort of offer too many tests.

The moral of the story is sort of don’t just — stand there, don’t just do something. But what we see is that owners are very quick on the trigger and — exactly. Denver has a first-year coach in Gary Kubiak.

HARI SREENIVASAN: Right. And you said also that players don’t necessarily — great players don’t necessarily make good coaches.

JON WERTHEIM: Right.

And it’s funny. Ron Rivera and Gary Kubiak were both NFL players, but they were not — these are not Pro Bowlers, just sort of serviceable players. And you look at the best athletes in sports, whether it’s Michael Jordan, or whether it’s Wayne Gretzky, not great careers as coaches and assessors of talent.

Well, why is that? And what we discovered is there’s something called the curse of expertise. And you get so good at a task, you skip steps, and part of the problem with that is, it becomes very hard to articulate what’s going on.

So, Michael Jordan was a brilliant basketball player, but he skipped steps to get there. And when it came time to instruct people, not great idea for a coach. The same way maybe your kid plays the violin, the best virtuoso in the world is probably not the best violin teacher.

What we see in sports is that like guys like Gary Kubiak and Ron Rivera, who they played, they didn’t pull these guys off the street, but they weren’t at that top echelon. They’re actually better able to articulate what’s going on.

HARI SREENIVASAN: And you mentioned that Jimmy Connors and Andy Roddick, that was one of those combinations where he couldn’t figure out how to tell him to improve his game.

JON WERTHEIM: No, the great Jimmy Connors, one of the most successful tennis players ever, and as a coach, it was fight harder, hit the ball.

For Andy Roddick’s next coach, he ended up going down a level, player Larry Stefanki, much less accomplished player than Jimmy Connors. He saw the game completely differently. And, again, he wasn’t afflicted by this curse of expertise.

HARI SREENIVASAN: OK. And there is this other thing in the book, and I want to get to it, is, are quarterbacks better looking on average?

JON WERTHEIM: Great archetype of sports, right?

HARI SREENIVASAN: Why is that?

JON WERTHEIM: No, the quarterbacks, whether it’s Tom Brady and Cam Newton, for that matter, at the highest level, or whether it’s the high school quarterback who dates the cheerleader, we have this idea in our head that the quarterbacks are the best looking guys.

And we actually devised an experiment. My collaborator, Sam Sommers, experimental psychologist, devised an experiment, where we actually tested that and sort of in a blind taste test assessed the looks of different players by positions. And quarterbacks actually ranked towards the bottom.

So why is it we have this archetype of quarterback as good looking? And there are a lot of factors, but we think some of it is, we’re conflating other qualities, right? This is the face of the franchise. This is the leader. This is one of the most important positions in sports.

And what we do, it’s called the halo effect, where we have qualities that we like in someone and we conflate all sorts of other qualities. So, we like Peyton Manning, and suddenly he becomes good looking in our eyes.

HARI SREENIVASAN: All right, Jon Wertheim, co-author, along with Sam Sommers. The book is called “This Is Your Brain on Sports.” Thanks so much.

JON WERTHEIM: Thanks, Hari. It was fun.