Life Science
Peter Suderman & Megan McArdle are getting married. One of my thoughts was, "How tall will their offspring be?" (assuming they are intent on producing any) I couldn't tell Peter Suderman's height from photographs with certainty, but he has confirmed they are the same height, 6 feet 2 inches. What sort of heights would we expect for the McSuderkinder?* Assuming 80% heritability for height, 3 inches as the standard deviation for both sexes, 5'10 and 5'4 as mean heights (male & female), and plugging into the calculator:
The highest probability of height for any male offspring: 6 feet 3.6 inches.
The highest probability of height for any female offspring: 5 feet 9.6 inches.
68.27% male offspring will be between 6 feet 0.6 inches and 6 feet 6.6 inches
68.27% female offspring will be between 5 feet 6.6 inches and 6 feet 0.6 inches
(1 standard deviation)
95.45% male offspring will be between and 5 feet 9.6 inches and 6 feet 9.6 inches
95.45% female offspring will be between 5 feet 3.6 inches and 6 feet 3.6 inches
(2 standard deviations)
In other words, there is only a 1 out of 40 chance that any given daughter will be taller than the world's tallest female econoblogger (though I assume by the time that any such daughter realizes such a height blogging will no longer exist). Blame Peter, he's less than 2 standard deviations above the mean....
* Or should I say the half-bloods?
Comments
"(though I assume by the time that any such daughter realizes such a height blogging will no longer exist)."
Could you explain this? The written word isn't going to disappear, nor is the internet. Or are you predicting the end of the world as we know it within twenty years? (Singularity 2029?)
Posted by: Z. M. Davis | July 6, 2009 3:08 PM
Where's your allowance for lying about height? Or does it cancel out as long as the chidren lie too?
Posted by: bioIgnoramus | July 6, 2009 3:23 PM
i assume page-by-page interaction with a notebook computer will be superseded by a more immersive media-info interface within the next 15 years. blogs to a large extent replaced the "personal homepage," so i assume that there will be something that supersedes blogs to give one a sample of an individual's thought stream.
(long form articles will remain, but i don't think that's blogging)
Posted by: razib | July 6, 2009 3:24 PM
please made sure and look at the standard deviation. the expectation is the *most* probable point on the distribution of possibilities, but not mostly probable.
Posted by: razib | July 7, 2009 12:31 PM
Razib,
Just curious, but do you think that children are getting generally taller, and are your height predictions based on current childhood growth data?
I'm 6' 1" and my wife is 5' 7" and it seems that our son (8 months) may be around 5' 10", as predicted by online calculators, based on his growth to date - but should I adjust these predictions upwards, based on current children growth rates??
The reason I suggest this, is having being screened by 23andMe, I see I carry 2 heterozygous alleles for low birth weight in infants - and hence maybe reduced size? But also, I see that my wife's nephews are so tall. Their Dad and Mom are 6' and 5' 6" respectively, yet their 12 yo son is 6' and about 200 lbs - and his doctor says he'll be at least 6' 4", as he is in the 99+ percentile for height - while his younger brother is 9 yo and 5' 3" and 140 lbs, so maybe even taller eventually.
Posted by: pconroy | July 9, 2009 10:07 AM
paul,
regression to the mean goes back to the population mean. but how do you define population? that's tricky, and i think it might be good to look at your extended families as a good proxy for a sense of what height there will be regression too.
the heights i'm using are for adults right now. i've heard that perhaps children are growing, but generally most of the variance in a given trial is going to be so high that i think small shifts in the mean are probably not that big of an issue.
Posted by: razib | July 9, 2009 1:50 PM
Razib,
Good point about "population" mean.
My grandfathers average 5' 7", my Dad and all uncles average 5' 8.5", my brother and all male first cousins average 5' 11", while on my wife's side her grandfathers average 6' 3", while her Dad and all uncles averaged 6' 1", and her brother and all male first cousins average 6' 2.5".
My wife also has a female first cousin who is 6' 2", married to a guy who is 6' 1" - similar to the original post - and their 5.5 month daughter is already as tall as my 8 month son?!
So I wonder where that leaves him potentially height wise?
Posted by: pconroy | July 9, 2009 5:30 PM
I don't know about the height, but since the child will be half-elf he will get +1 to agility.
Posted by: I_Affe | July 10, 2009 10:47 AM