Heck no - my little sister runs rings around me. Travels to distant lands, too, just as the NYTimes article suggests she’d tend to.
My family generally considers me to be the smartest. My Dad would never make such a distinction, but both my Mother and my Sister think that I am smarter than my little sister.
I only have one daughter though, and she is by far the smartest of my children to date. 
Yes.
-Erin, oldest of three
I have one younger brother, 5 years below me. From a purely academic standpoint - yes, I am smarter than him (and have a higher IQ, FWIW). However, I think it has less to do with an actual difference in intelligence and more to do with the fact that he’s a lazy ass, bless his heart.
Hm. I was reading the article on the BBC website, and there was a suggestion that first-born children get more attention from their parents, contributing to higher intelligence. I think that might be true in my family, anyway - my mom always tells me how obsessed she was about making sure I had those toys from Fisher-Price that are supposed to boost your infant’s intelligence and things of that sort. It’s a cliche, but I always had more pressure to excel than my brother did, simply because I was the first child. By the time my brother was born, my parents had mellowed out a bit.
No. I’m always haunted by the lurking near-certainty that my younger sister is smarter than me 
She certainly achieved more in school (at least until college) than I did and did a lot better than me on the SATs. As a kid, I generally tried to avoid competing directly with her, as the NYTimes article says younger siblings tend to do.
It does apply in Mr. Neville’s family, though- he’s the oldest of 3 boys, and I’m pretty sure he’s smarter than both of his brothers.
Not sure in my mom’s family.
I’m pretty sure my dad is smarter than three of his four younger siblings, but his youngest brother is probably smarter than he is.
My younger brother is the higher achiever with a doctorate in Aerospace Engineering, partial ownership of a wind power company, etc. but I’ve always tested higher. He’s actually told me he thinks I’m actually smarter I’m just lazy (although I don’t know if he just said that to motivate me).
Hell no, youngest of five.
My parents were burnt out by the time I rolled around. My eldest sister, the hippie, went through hell to break them in.
by all standards the 2nd and the 3rd are far smarter in my family of 6
It may have been hard to tell when we were growing up. But considering how things have worked out, if you take into account who got where and how: definitely.
- oldest of three and one adopted.
I’d like to think not, since I have an older sister.
It’s true in my family.
Youngest of 3 and my eldest brother is doing best out of all of us.
Yes. I’m the oldest of four. Two of my younger siblings have higher education than I do, and at least one of them makes more money, but they would admit that I exceed them in raw intelligence. I kill them in Trivial Pursuit, Scrabble or chess, but they hand me my ass in the classroom. 
No. I’m much more booksmart than my older brother, and we’re a year and a half apart in age.
Priam - youngest of two
My sister - the oldest - tested out at genius level as a youth. However, she never did anything with her brains and as far as I can tell, never learned common sense either.
I was above average in school, but always had to work for what I achieved. I am the youngest.
My brother is older than me, and smarter.
Pop’s an only child.
Mom I think was the youngest of three, but was the smartest. Although her remaining big brother is pretty smart too.
-
Big brother: most educated, makes the most money, has zero interpersonal skills
-
Me: Some education, make okay money, get along well with most people
-
Little sis: dropped out in 8th grade, jumps from job to job, is loved by everyone she meets
So, the oldest in my family has the most book-smarts and the youngest has the most people-smarts.
Our family pretty much concurs that the eldest (girl) got the looks; the middle (boy) got the personality; and the youngest (girl-me) got the brains.
We also agree that my oldest sister had the most responsibility - and is the most mature; my brother was spoiled rotten - and got into the most trouble, and I was mostly left to my own devices - and am pathologically independent.
I’m the oldest of five. I’m reasonably bright. #2 is at least as smart as I am, but also the least interested in institutions or success on paper. #3 is the one getting the PhD and studying a zillion languages. #4 is the computer/engineering whiz working for the fancy lab. #5 is still in college, and is young enough to count as a new batch. So which one of us is smartest? Pretty impossible to say, I think. We’re all so different.
Of my husband’s family, he is #2 of 6, and is probably the smartest one in science/math stuff, but the oldest and #3 are right up there too.
If we’re going by education level, #5 (out of 10) in my family is the smartest; she’s an MD. All of the first 9 have a degree of some sort wheres I (#10) never went to college.