Physical reasons Ranma would choose one form over the other

[antimatterenergy]

Topic is for physical differences between men and women as they may relate to Ranma, not social or psychological (tons of those as well). Ranma may notice over time that some of these things are easier to do as a female and others easier as a male.
Ranma would probably choose to be male while drinking alcohol because physically larger and because males have an extra enzyme in the stomach lining which breaks down some of the alcohol so less reaches the blood stream.
If injured or having to experience pain Ranma is more likely to change to a male because women were found to have both a lower pain threshold and tolerance in several studies. Several studies have also shown that it is not because of psychosocial origin.
If Ranma is forced to do public speaking of some type he may choose to be female because several studies have shown that when speaking the brain seems to be very focally organized in women compared with men.
If Ranma has to do something that requires fine motor control he would probably choose to be female because of smaller fingers and because the female brain is better organized for fine motor control of the hands.
If Ranma was traveling he may choose to be male because the male brain is better at spatial directions. (Ryoga would hate turning into a girl if for no other reason this.)
If taking math Ranma may choose to be male because the male brain is better organized for mathematical skills.
If he needs to recall a memory he maybe able to recall things better as a female since studies have shown that females have a better memory then males.
Maybe better off playing poker while female because recent studies have shown that females are better at differentiating emotions in others. Except for anger males are much better at telling if someone is angry. This is thought to be because of differences in the brain not how the person was brought up.
If has to walk through rose bushes better off as male because male skin is %25 thicker.
If need to feel stuff in detail better off females have more sensitive touch because of the differences in male and female skin.
In eating there are genetic differences in taste perception and differences in the density of taste buds on the tongues between males and females so stuff would taste different depending on what sex you are.
Strength - male
Fit in tight space - female because smaller
Reach something farther away without getting up - male because taller
This doesn't mean that a girl/ guy can't be better at the thing listed then most of the opposite sex just that biologically speaking there is a difference and if xx was changed to xy the difference would most likely be noticeable after time.
I've been reading too many science/health magazines.
What other physical differences may cause Ranma to change sex for the benefits (caused by the physical differences)?

[Pale Wolf]

Smell and hearing. Females tend to have a better sense of smell, males tend to have a stronger sense of hearing.

[Knight of L-sama]

Well it's established in canon that while Ranma is stronger than most people in either form but his male form has more strength than his female form (probably due to greater muscle mass given the difference in physiques) so Ranma would probably prefer his male form where brute force is the primary requirement.
When searching for something Ranma might prefer female form since on average women have better peripheral vision than men.

[mondu_the_fat]

Men do not have to go through ovulation and menstruation.

[TerraEpon]

Men do not have to go through ovulation and menstruation.

That's assuming Ranma-feamle does.
-Joshua

[mondu_the_fat]

Considering that from antimatterenergy's statements that the changes are right down to the cellular level, why not? This would be like saying that, for the sake of this discussion, Ranma is completely female, including the brain wiring and memory capabilities of females, but not ovulating, because, well, we never see him menstruating in the manga.
This entire thread rests on the assumption that ranma is completely female on transformation, including differences that are brought about growth and development (considering that Ranma never grew up as a female). Why on earth should we exclude menstruation?

[Atlan]

Dont forget, the musk used Jusenko to make brides. That means that the transformation goes right down to the plumbing. The only difference between them and ranma is the locking ladel.
One might imagine that ranma dosent go through menstruation simply because he isnt female long enough for it to happen.

[Pale Wolf]

Or that he does and Takahashi just didn't feel like showing it.

[Zwzn]

Dont forget, the musk used Jusenko to make brides. That means that the transformation goes right down to the plumbing. The only difference between them and ranma is the locking ladel.

The problem with this assumption is that we don't know what gender the animals were before the drowned girl water. It may be that onlyfemale creatures that fall in can have kids. I can't remember Ranma acting differently as girl then a boy. This is one reason I think Ranma gets free food from venders when he is in girl form. They think he is flirting when he is just acting like a boy/himself in a girls body. Ranma may think they just give out stuff to all the girls. This is actually some what suported by his comment he made about girls having it easy just before he came upon his schools rhythmic gymnastics team getting beat up by Kodochi.
The only times I can remember him acting differently is when he means to.

One might imagine that ranma doesn't go through menstruation simply because he isnt female long enough for it to happen.

He does seem to spend as much time if not most of his time as a boy. He may just never have the right hormones in his sytem.

[Zwzn]

Or that he does and Takahashi just didn't feel like showing it.

I personally doubt that that. It would have been a good way to make Akane look good, and could have been very funny.

[Pale Wolf]

The problem with this assumption is that we don't know what gender the animals were before the drowned girl water.

Gender's a rather small consideration considering the radical changes in biology and genetic code that'd be necessary to even dream of using animals as breeding stock.
The changes have to go right down to the hormonal/cellular level even to make breeding with an already-female animal possible.

I can't remember Ranma acting differently as girl then a boy. This is one reason I think Ranma gets free food from venders. They think he is flirting when he is just acting like a boy in a girls body. The only time I can remember him acting differently is when he means to.

Uh... I assume this is not counting the time she gave flirting lessons to those two mirror twins/clones/whatevers?
Ranma does flirt. Most likely as a psychological ploy rather than a sign of interest, but she still acts that way.

[Forum Troll]

http://en.wikipedia.org/wiki/Pregnant_Ranma_problem contains a paraphrase of Takahashi's stance on the subject.
I read it as Ranma does go completely female, but the consequences of that are not appropriate within the context of a comedy story.
Troll

[Zwzn]

The problem with this assumption is that we don't know what gender the animals were before the drowned girl water.

Gender's a rather small consideration considering the radical changes in biology and genetic code that'd be necessary to even dream of using animals as breeding stock.
The changes have to go right down to the hormonal/cellular level even to make breeding with an already-female animal possible.

It is magic it does not have to make sense to science. I was thinking it might do different things depending on gender and animal.

I can't remember Ranma acting differently as girl then a boy. This is one reason I think Ranma gets free food from venders. They think he is flirting when he is just acting like a boy in a girls body. The only time I can remember him acting differently is when he means to.

Uh... I assume this is not counting the time she gave flirting lessons to those two mirror twins/clones/whatevers?
Ranma does flirt. Most likely as a psychological ploy rather than a sign of interest, but she still acts that way.

That time he ment to flirt, and he was trying to pick up a guy. Lastly the stuff he did was somewhat over the top, and not something he would likely do if it was not for the reason he was doing it.
Basicly I find it unlikely he did what he did when training the mirror clone to get the free buns.

[TerraEpon]

One might imagine that ranma dosent go through menstruation simply because he isnt female long enough for it to happen.

This is the most likly case, yes, IMO.
-Lala-

[Pale Wolf]

It is magic it does not have to make sense to science. I was thinking it might do different things depending on gender and animal.

While that is possible, it doesn't make sense. Sense is sense, regardless of whether science is involved. Just because I use semi-scientific terms doesn't mean that it suddenly involves a radically different mode of thought.
Saying it 'might' have a different depth of change depending on gender and species is technically possible, if only because Takahashi hasn't said anything to the contrary. However, if you can't come up with a reason why it might, then I don't think it's a theory worthy of consideration.

Basicly I find it unlikely he did what he did when training the mirror clone to get the free buns.

And then where would he have learned those skills?