STEVE INSKEEP, HOST:
NPR's social science correspondent Shankar Vedantam is with us once again. He regularly drops by to chat, and he has some new social science research today about siblings. Turns out that if you have an older sister, it can change your life. Shankar, how?
SHANKAR VEDANTAM, BYLINE: Well, Steve, there's been tons of research looking at siblings and birth order and having older and younger siblings.
INSKEEP: Sure, Marcia, Marcia, Marcia.
INSKEEP: Pop-culture - go on, go on.
VEDANTAM: The new study adds another layer to this mountain of studies. Economist Hiroko Okudaira and her colleagues examined the behavior of Japanese high school and college students and specifically competition and competitive activities. Women with older sisters tend to be more competitive than women who do not have older sisters, whereas men with older sisters tend to be less competitive than men who do not have older sisters.
INSKEEP: Woah, woah, woah, woah, woah, so somehow the other sister is inspiring the younger sister to come on and be competitive but stifling the younger brother, is that what's happening here?
VEDANTAM: Well, you know, again, there are a ton of theories about why siblings and birth order can have these effects on us. Many of the theories contradict one another. One theory might suggest that men with older sisters are socialized to be more cooperative from a very young age, whereas women with older sisters need to claw their way to get the attention of their parents. Now, I think the thing to remember here is that this is just another layer in a vast mountain of studies. It's not really a good idea to take the study, apply to your own life, and say now I understand why my younger sister is always so competitive with me.
INSKEEP: Lucky for your older sister that you're so understanding.
VEDANTAM: That's exactly what I tell her all the time. She does not believe that, Steve.
INSKEEP: That's NPR's Shankar Vedantam. He's on Twitter at @HiddenBrain. We're at @MorningEditon, at @NPRInskeep, at @NPRGreene, and @NPRMontagne. Transcript provided by NPR, Copyright NPR.