STEVE INSKEEP, HOST:
Every Saturday evening inside a blue house in Odessa, Texas, you hear this.
(CROSSTALK)
UNIDENTIFIED PERSON #1: This is the fresas with crema.
UNIDENTIFIED PERSON #2: That's perfect.
UNIDENTIFIED PERSON #3: That's good.
INSKEEP: The Almance family gets together, cooks together, including the family's special taco recipe, and they laugh together.
(LAUGHTER)
CINDY ALMANCE: Tell daddy and you, and he was like, ma (laughter).
INSKEEP: This is much more than a good time because layered into that social gathering is a way to teach brothers and sisters to stop fighting and care for each other. For our series, The Science of Siblings, Michaeleen Doucleff traveled to the family's home in West Texas.
MICHAELEEN DOUCLEFF, BYLINE: Several months ago, Caitlynn Almance graduated from college. She's 22 years old. And as she thinks back to high school and college, she's had the same best friend the entire time.
CAITLYNN ALMANCE: My sister is my best friend in the entire world, and I tell people that all the time. I don't think I could, like, make it, like, day-to-day basis without her. Like, she's the person that I depend on for everything.
DOUCLEFF: Caitlynn grew up in Odessa, but she went to college in another town two hours away. Sometimes her sister, who's still in high school, will call up Caitlynn and ask her to borrow her clothes or a pair of boots. And Caitlynn would stop what she's doing and drive four hours.
CAITLYNN ALMANCE: There was one time that I had, like, just like a four-hour break. That's all I had. And I drove all the way down, like, dropped it off in the front door and, like, took all the way back off to, like, Alpine. It's 'cause she needed it. She needed it. And, you know, in that moment, she really does need it.
DOUCLEFF: Caitlynn's love and caring doesn't end with her sister. She feels the same about her little brother. A few years ago, she seriously considered moving with him to Los Angeles to help support him through school.
CAITLYNN ALMANCE: And I was like, look, Eddie, if that's what you really want to do, like, I'll, like, get up, and I'll pick up my life. And I'll move over there, and I'd work.
DOUCLEFF: To help him pay for schooling?
CAITLYNN ALMANCE: Yeah. Yeah. And so he wouldn't have to struggle either. 'Cause I know, like, how hard it was for me to, like, work and go to school at the same time and, like, juggle. And, like, if he doesn't have to do that, then I wouldn't want him to do that.
DOUCLEFF: For the past few decades, scientists have been studying how parents all around the world teach their children to build deep, fulfilling relationships with their siblings. Belinda Campos is a psychologist at the University of California, Irvine. She says that in Latino families like Caitlynn's, parents are often doing something very specific, and scientists can even see what it is inside the brains of young adults. In one study, researchers brought college students into the laboratory from two cultural groups.
BELINDA CAMPOS: They had European American and Latino participants come in, and they had them play a resource game.
DOUCLEFF: During the game, the students had to decide whether or not to help a family member who needed money.
CAMPOS: Both groups assisted their family members when there was a perceived need.
DOUCLEFF: But here's the key. While the participants gave their family money, the researchers studied their brains with an MRI scanner. What happened inside the brains of the Latino participants was quite different than inside European Americans' brains. While giving their family money...
CAMPOS: The brains of the Latino participants - the reward centers of the brain lit up when they were doing so.
DOUCLEFF: In fact, their reward centers lit up more when they gave money than when they received money themselves. But that didn't happen with European American students.
CAMPOS: It makes such a compelling argument that some of us find the act of giving - or because we're socialized to - to be, like, really rewarding.
DOUCLEFF: Now, the reward center of our brains helps us feel pleasure and joy. Mariano Rojas is a behavioral economist at Mexico's Technology Institute. He says many studies, including his own, show that Latino parents often teach their children not so much that they have to help their siblings, but to actually want to help their siblings. And they do that by teaching them that helping brings you joy.
MARIANO ROJAS: It's about enjoyment and relations that provide happiness.
DOUCLEFF: In other words, helping your sister - bringing her a pair of boots - isn't so much a huge burden or obligation, but a major source of joy in your life. It gives children...
ROJAS: What I call relational wealth.
DOUCLEFF: This relational wealth has massive repercussions for Latin American communities. Rojas' research finds it's the major reason why people in these communities tend to score very high on surveys about happiness.
ROJAS: Latin Americans perform outstandingly well. Their happiness is very high.
DOUCLEFF: That's across all economic levels.
CINDY ALMANCE: The funniest story of my life.
DOUCLEFF: Back in Odessa, the sun has just set over the dry West Texas prairie. It's around dinnertime, and the Almance family is doing what they do almost every day. They're gathered around the kitchen island. There's Caitlynn's grandmother, her parents, an aunt and an uncle. They're telling stories about trips they've taken all together and reliving all the fun.
CINDY ALMANCE: Welcome to the family. I mean...
DOUCLEFF: That's Caitlynn's mom, Cindy. I asked her, how do you teach children to find joy in helping their siblings?
CINDY ALMANCE: It's the modeling, right?
DOUCLEFF: Modeling. And what Cindy models is the joy she gets from the relationships she has with her own brothers and sisters.
CINDY ALMANCE: I guess it's a close, close bond.
DOUCLEFF: Even after some of her siblings left Odessa, she still loves to talk to them on the phone.
CINDY ALMANCE: You know, 6:30 in the morning on my way to work, I'm talking to them already, but it's every single day.
DOUCLEFF: And her daughter Caitlynn not only notices these calls - she even joins them.
CAITLYNN ALMANCE: My mom's older sister, they're in a different time zone than we are, so they have to wake up an hour earlier than their day would start, just so that we could, like, have that, like, daily, like, dose before we get to work.
DOUCLEFF: Perhaps most importantly, Caitlynn says, is the family enjoys being together - multiple generations of brothers and sisters all having fun together.
CAITLYNN ALMANCE: This is, like, your everyday people. And they have such, like, an everyday impact on my life rather than, like, us, like, searching each other up on Facebook. Like, that doesn't exist. Like, we all know each other.
DOUCLEFF: And now Caitlynn is going to add the next generation of siblings. She's expecting her first child this summer, and she's already talking about having a second baby.
CAITLYNN ALMANCE: This one isn't even out yet, but I'm like, let's hurry up and make the other one.
DOUCLEFF: Why? Because she wants her baby to have a sibling right away.
CAITLYNN ALMANCE: Just, like, imagining my kid growing up without that - there's probably nothing worse than that. That would be, like, the biggest sin I could ever imagine.
DOUCLEFF: For NPR News, I'm Michaeleen Doucleff.
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INSKEEP: Hey, join us tomorrow for a story of identical twins. Both are autistic and have different experiences.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
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