Are big brothers always bigger?

During a discussion in the pub the other night my friends and I noticed that in the cases where one of our friends had a male sibling the one born first was always taller. We are aged about 23/24 so can be considered to be fully grown. We figured that one of two things must be true, either it is a great coincidence that the first born is always taller in all the cases we could think of, (we had a sample of around 10 pairs of siblings), or something else was going on.

So what is the straight dope on this? Is there any statistical evidence to show that the first born of male siblings remains taller when both are fully grown and if so why is this the case?

I’m taller that my big brother & half brother and all my sisters. My youngest daughter is definitely going to be bigger than her older sister. Now how’s that for some impressive statistics?!

Thanks for the reply but I was looking for something more concrete than anecdotal evidence. We did notice that it didn’t seem to be true amongst female siblings, just males. I suppose it is entirely possible it was just a coincidence amongst the sample available to us but I was hoping someone could provide a link to some statistical data taken from a larger sample.

I am about 1.90m. My brother is four years younger than me (I am 29), and close to 2m. So it’s not always; I don’t know if it happens more often than you’d statistically expect.

Jeez - what do they feed you in the Netherlands? :eek:

My little brother (okay, so he’s not little anymore, and he was never that much younger than me) is about 2 inches taller than I am.

I have two sons, aged eleven and nine. My younger son is currently about a quarter inch taller than his older brother. My best guess is that when they are adults, my oldest will be about six feet and my younger one will be about six-four.

Zev Steinhardt

This study found exactly the reverse: that older siblings are significantly shorter than younger ones.

Lots of starch-rich food, mostly: potatoes, pasta and rice tend to be on the menu a lot. Don’t know if that is the explanation, though. Maybe we evolved to keep our heads above the water, next time the country is flooded again. :smiley:

While me and li’l bro are above-average even by Dutch standards, we’re hardly exceptional, and I regularly meet people (men, actually) who are a head taller than me.

More anecdote!

My younger brother is also taller than I am.

I’m the oldest of three boys, and both of my brothers are taller than I. Of course I could still whup both their asses if need be… :wink:

Looks like this is mostly what you are going to get. :wink:

??? Your hypothesis is based on anecdotal evidence. And since it includes the word “always,” all it takes is one exception to disprove it. When you come up with an idea that’s wrong and easily disproven, it’s really going overboard to insist on published study results.

To be fair, it only takes a single anecdote in the negative to answer the original question with a resounding “no”.

-lv (6’2", 250lb little brother to a 5’6" 150lb guy)

My husband is 6’1", while his younger brother is 6’4".

My father is a good 3 inches shorter than his younger brother.

I’m 5’9", my younger brother’s 5’11", my two youngest brothers are taller still. In my dad’s family, his oldest brother is really short, like 5’6" or so, and his youngest brother is 6’4" (tallest in the family.) So I think your theory is swiftly going down the tubes. :slight_smile:

I don’t think there is a general rule that big brothers are always bigger. I’m the oldest son and I’m taller than my brother. But look at the Bush brothers. George W. is older than Jeb, but Jeb is taller by a few inches.

My biggest relative (about 6’4") is the 10th of 11 children, including two other brothers older than him.

Three sons. Middle is shortest, oldest and youngest are about equal.