# Why do men have nipples? **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [April 10, 2009, 3:25pm UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649 "2009-04-10T15:25:20Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [April 17, 2009, 11:28pm UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/21 "2009-04-17T23:28:10Z")
The point was, you said that insects are the most successful species and then defined “successful” to be most offspring. Under that definition, insects are not the most successful species, some species of fish or coral are (I’m not sure what individual species produces the most offspring per organism; can’t seem to get a definitive answer anywhere). ---
**Author:** ![johna](https://avatars.discourse-cdn.com/v4/letter/j/eb9ed0/32.png) [@johna](https://boards.straightdope.com/u/johna)\ **Post date:** [April 18, 2009, 9:40pm UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/22 "2009-04-18T21:40:13Z")
> [@Mijin](#): > > The point was, you said that insects are the most successful species and then defined “successful” to be most offspring. > Under that definition, insects are not the most successful species, some species of fish or coral are (I’m not sure what individual species produces the most offspring per organism; can’t seem to get a definitive answer anywhere). I did say that insects are the most successful species, but I didn’t define success. I did say they are successful due to their ability to have many offspring, but not that success is having the most offspring. As to the definition of success, that’s harder to pin down especially when the population mutates. Is a lineage successful if it remains essentially the same (e.g. like crocodiles and sharks)? Or is a lineage successful if it mutates but one or more variants of it continue on? I know it’s a hazy definition, but to me insects are successful because there a huge variety of them and they have survived in one form or another for millions of years. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [April 18, 2009, 10:34pm UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/23 "2009-04-18T22:34:33Z")
> [@johna](#): > > I did say that insects are the most successful species, but I didn’t define success. I did say they are successful due to their ability to have many offspring, but not that success is having the most offspring. Right. “Most successful species” is wholly dependent on what a given human has defined “success” to be. That’s why, it was pretty meaningless to say “The most successful species on earth are not us, it is insects”. ---
**Author:** ![johna](https://avatars.discourse-cdn.com/v4/letter/j/eb9ed0/32.png) [@johna](https://boards.straightdope.com/u/johna)\ **Post date:** [April 19, 2009, 8:27pm UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/24 "2009-04-19T20:27:24Z")
> [@Mijin](#): > > Right. “Most successful species” is wholly dependent on what a given human has defined “success” to be. > > That’s why, it was pretty meaningless to say “The most successful species on earth are not us, it is insects”. Ok. Another tack is to say success is not a failure. What is a failure from an evolutionary perspective? ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [April 20, 2009, 10:00am UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/25 "2009-04-20T10:00:24Z")
> [@johna](#): > > Ok. Another tack is to say success is not a failure. What is a failure from an evolutionary perspective? We’ve really gone round the houses here, my point was simply that it’s meaningless to say insects are the most successful species, not humans. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [April 20, 2009, 10:15am UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/26 "2009-04-20T10:15:27Z")
(adding to above post…) A species can be the most long-lasting, or most populous or whatever. But “most successful” is rather more subjective. Also, it’s a little unfair to compare a class to a species. ---
**Author:** ![Curamachado](https://avatars.discourse-cdn.com/v4/letter/c/13edae/32.png) [@Curamachado](https://boards.straightdope.com/u/Curamachado)\ **Post date:** [April 20, 2009, 2:28pm UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/27 "2009-04-20T14:28:34Z")
Guys, Male nipples ARE an effective evolutionary tool! Higher sensivity in the nipples fosters more and better sex; hence more babies (with niples sensitvity); hence perpetuation of males’ nipples. Simple! ---
**Author:** ![Lukeinva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lukeinva/32/17872_2.png) [@Lukeinva](https://boards.straightdope.com/u/Lukeinva)\ **Post date:** [April 27, 2009, 10:56pm UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/28 "2009-04-27T22:56:45Z")
All fetuses start as female, and with nipples. Only if the Y chromosone is delivered by the male will the sex will be a male. But the nipple remains, since they were there to begin with. ---
**Author:** ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)\ **Post date:** [April 28, 2009, 2:50pm UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/29 "2009-04-28T14:50:16Z")
> [@lukeinva](#): > > All fetuses start as female, and with nipples. Only if the Y chromosone is delivered by the male will the sex will be a male. But the nipple remains, since they were there to begin with. Either your English composition skills or your biology need serious work. The Y chromosome is either there or forever not there by the time a fetus A) exists or B) has any anatomy of any kind. ---
**Author:** ![Irishman](https://avatars.discourse-cdn.com/v4/letter/i/b487fb/32.png) [@Irishman](https://boards.straightdope.com/u/Irishman)\ **Post date:** [April 29, 2009, 4:15pm UTC](https://boards.straightdope.com/t/why-do-men-have-nipples/492649/30 "2009-04-29T16:15:25Z")
All fetuses start with undeveloped sex organs of both genders. Depending upon hormonal triggers during development, different sex organs will develop and the others will fade. In the absence of a Y chromosome, the X chromosomes will send female hormone triggers. Since all babies have X chromosomes, they will tend to default to female. [Previous page](https://boards.straightdope.com/t/why-do-men-have-nipples/492649.md?page=1)