Shared publicly  - 
This explains so much about my President's Challenge failures as a child. 
Hannah Grimm's profile photoChris Burbank (Windam)'s profile photoIngo Oeser's profile photoTraci Tenkely's profile photo
I feel the same way. I am 6'8" and can barely do a pull up. I have fairly low body fat and I work out 3-4 times a I am by no means weak. But my arms are so long, it is very hard to do a pull up. 
So very interesting... and I'm guessing if your arms are long compared to your body that would also affect things... hmm....
It makes me wonder how many pull-ups the average olympic swimmer can do :)
Brings back some not-at-all fond memories of gym class when I was a kid.  Thanks for posting this explanation!
I am 5'5" and it took me a year of climbing workouts before I could do a pull up. And I still have to jump a bit to get the start.
At my high school they told us if we didn't have the vertical leap to reach the bar without assistance we were excused from trying the exercise. So about six or eight people did it (I can't recall if any were female) and being 5'2" that did not include me.
Eh.  I can do pullups just fine.  The middle school girls that I teach circus to?  They can do them too.  I think it's just that girls don't start doing them early enough.
Wow, that explains finally, why it has always been easy to outperform even the best athletes at school with this.