Well, I don't know if the kid was confused himself then, or just playing with me. Still embarrassing no matter which gender's naughty bits it references.

I believe the correct word is "sex", though oddly that word seems to have offended enough people to the point that the incorrect substitution of "gender" is now commonplace...

How is gender not the correct word when talking about the traits of a particular sex?

The word gender applies to the cultural traits of a particular sex. In contrast, sex applies to the biological traits.

Example 1: Jamie is a woman [sex] whose friends say she her inability to ask for directions makes her very masculine [gender].

Example 2: Jamie has never let her sex influence her behavior in the office no matter how much her co-workers believe she should fit the stereotype of her gender.

Sadly, this is one of those concepts that is dying as time goes by. More and more 'sex' is just shorthand for 'sexual intercourse'. So the word 'gender' is taking over what 'sex' used to mean. Someone needs to come up with a new word, or feminist discussions are going to get really really hard...

(PS-- Example 2 is pretty funny when we use the new colloquial term...)

According to Merriam-Webster, gender is the behavioral, cultural or physiological traits associated with one sex. Maybe I'm not getting the nuances here.

I can see how in technical or scientific communication, the difference would be important, for accuracy's sake, but in common conversational usage, those words really have become virtually interchangeable.

Can you provide a more detailed source? The version of the definition given in this online version of merriam-webster says something different from what you quoted...
http://www.merriam-webster.com/dictionary/gender

That is exactly what I was bemoaning - what I assume is misplaced prudishness about the word "sex" has led to the incorrect useage of "gender" becoming commonplace - it has been going on for some time, but recently, I have even seen the "M" and "F" checkboxes on forms listed under the heading "Gender".

I know, it's a losing battle and the language, etc. will go on evolving whether I approve or not, but for now, I think "gender" is still considered incorrect. In terms of "wrong" becoming "right" by virtue of common useage making it the de facto standard, it doesn't bother me as much as, say IE once did, or cheap calculators not obeying "order of operations" but I do notice whenever I see it...

Perhaps Jasen just incorrectly read or typed the word psychological as physiological?

As I understand it, there are some who claim that not only "gender" but also "sex" is socially constructed, that there is no bodily subject behind the roles. In other words, that there is no such thing as different male and female physiology, neurology and consequent psychology. This is part of the culture wars, part of the assault on science. If everyone actually believed that, we should maybe go extinct; which would be a good thing, as it would reduce the sum total of idiocy in the universe.

Well damn, I think I did. I could have sworn that link said physiological.
Perhaps I need to see an optometrist. :)

Yes, I see your point now.
Sex is the body, gender is the mind. So a homosexual, for instance, can be one sex but have the opposite gender.

Well, no. A male homosexual is not usually socially-constructed as of the "female gender". Nor do I think he ought to be so socially-constructed unless he wants to be. Some homosexuals seem to be what we might call hypermale, and I don't think these have any desire to be or seem female. The sex/gender distinction is more relevant to those people who seem to themselves to be trapped in the wrong body, those who are born with a female mind in a male body (it is rarely the other way round). I believe such people are called transgendered, which seems to me to be a contradictory usage. For if the body is sex and the mind is gender, they only have the one gender, which is female, although their bodies are male.

The point of all this is that the human sexes are not as simple as we are led to believe, even physiologically. By no means everyone is born with wholly neat and tidy "his and hers" equipment. The default human being is female, and to make a male a lot of embryological development has to be done just so, and can easily go wrong. Especially if the mother is stressed during her pregnancy; there was a darn good reason why everyone used to make her spend the months in peace and quiet.

I said "can", not necessarily is.
I know several transvestites here, which is what I thought of. They truly do act like women in men's bodies. I don't particularly care for the term "transgender" in that case either.

This statement, while not strictly incorrect, is very misleading. To say that the default human embryo is female is correct. A male embryo will not develop without the presence and activation of a couple of genes on the Y chromosome. If those genes are present, but don't activate, then the resulting fetus, if viable, will be genetically male while physiologically female. However, this is a very rare occurrence, and in general it is no less complicated to make a female fetus than it is to make a male fetus.

This is not to be confused with some other species (some fish and some insects), where the egg develops into a female in the absence of sperm from a male. In these species, the girls don't have fathers!