What determines the penis size you are born with?

[Ivor]

I wish Sherlock holmes or more preferably Miss Marple would do a "who dun it" so we could finally discover which side of the family dick size comes from.

This is actually a really good question. I expect the genetic code that actually tells your body how to make a dick and balls is entirely on the Y chromosome since there's no reason why a woman's body would need to know how to make them - but OTOH I think testosterone is a big factor in determining size and both men and women produce testosterone. It's testosterone that leads to male baldness and it's said that whether your mum's dad went bald early is a better indication of what you can expect than whether it happened to your own dad.

[Lazy 8]

Here's an answer from Ask Alice based on someone else's question to her website:

After some genital gymnastics herself, Alice wound up in Washington, D.C. before finding an answer to your penile pondering. According to the National Center for Genome Research at the National Institutes of Health, penis size, like height, weight, and general build, probably comes from both mom and pop. Research on size-related genital genetics is scarce because funds and brain power are, understandably, spent on finding treatments and cures for genetic disorders, like human growth hormone deficiency, which can cause stunted penile development. Alice hopes that this information doesn't cause you to lose a bet, or, worse yet, start a family feud.

[Thick_Unit]

Alice hopes that this information doesn't cause you to lose a bet, or, worse yet, start a family feud.

Yes all of my uncles are jealous of it. It went as far as not being invited to any family gatherings.

[wind chill]

You get 50% of your genetics from your mother too though. Just because she doesn't have a penis doesn't mean she doesn't have genetics that effect YOUR penis.

I think i got my penis from my mothers side like 100%.My dad has a big flaccid,almost as big as mine erect.
Conclusion- if you get your penis from your mothers side you are screwed big time in the genetics department.

[Tamora]

I think i got my penis from my mothers side like 100%.My dad has a big flaccid,almost as big as mine erect.
Conclusion- if you get your penis from your mothers side you are screwed big time in the genetics department.

Don't know about my mother's side...but I do know my ex wife had a huge penis.

[Jay1983]

Don't know about my mother's side...but I do know my ex wife had a huge penis.

Now I'm jealous.

[Tamora]

Now I'm jealous.

You wouldn't be if she F'd you up the arse too!

[Jay1983]

You wouldn't be if she F'd you up the arse too!

Now you're teasing me.

[Tamora]

Now you're teasing me.

Everyone wants to race me in my TT! That's teasing!

[Party]

I'm trying to find something funny to post. But I'm at a loss. Sorry.