[emgoldstein]

No, I'm asking you to produce evidence for a hypothesis you seem to believe. I don't have any hypothesis of my own.

If you tell me that the Sears Tower and the Empire State Building are the same height (a hypothesis), you should show up with evidence that they are the same height, or some other a priori reason to believe that your hypothesis is more likely to be true than untrue (for instance, if both buildings were the product of the same prefab factory).

[1] is a rat study. How it relates to any hypothesis about XY versus XX humans is beyond me.

If XX and XY humans have different interests/aptitudes, that's a very parsimonious explanation for the toy aisle at Walmart, right?

But if your hypothesis is true, we need to search for other explanations. For instance, Walmart and other toy stores might be controlled by a conspiracy of conservative Christians who believe in different gender roles, and are willing to sacrifice profits (from boys buying Barbies, girls buying cars, etc) to support their goal of an unequal society. Is this the hypothesis you're proposing? It also needs to apply to Target, etc, all of which have the same boy/girl aisles.

[mdorazio]

The fact that you asked for "evidence that XX-chromosome humans have the same distribution of interests and aptitudes as XY-chromosome human" shows that you believe the opposite. Otherwise you wouldn't ask for the evidence in the first place. And I just gave you some evidence, but you seem to think it's not good enough. That's about as good as the research gets, which is itself a commentary on how little the scientific community seems to think this line of questioning is worthwhile. But fine, here's some more: https://books.google.com/books?id=xeYJAAAAQBAJ&lpg=PA110&ots...

I'm trying to figure out how you would even begin to do an objective study of what you're looking for since by the time kids present meaningful interests, they're already irrevocably influenced by society and their parents' expectations.

And no, that's not a parsimonious explanation at all, it's one of many that fits a particular narrative. Equally plausible is that toys today are a relic of thousands of years of traditional gender role pressures that have no place in today's knowledge economy. You can trace "dolls are for girls" back to hunter-gatherer times where it made sense for boys to be given knives and bows, and girls to be given baskets and dolls. The problem is those roles are deeply ingrained in today's society even though they don't make much sense anymore since today women are more likely to build robots than men are to hunt their own food.

[1] Is a genetics study, the very thing you're asking for evidence of. That's how you would test a hypothesis that genetics is key to occupational interest -- look at two animals with identical genetics and see if they show the same interests regardless of environmental factors. If they don't, then the entire XX vs. XY distinction is a moot point. i.e. if two people with literally the same DNA don't show the same interests (as is the case for many identical twins), that's rather strong evidence that genetics doesn't mean much for occupational choice at all. And if you're discounting the study merely because it uses rats, you're going to have to throw out an awful lot of research from the last 100 years on just about everything related to biology.

[emgoldstein]

Your evidence (of the absence of sexual dimorphism in the human brain) is that rats with identical genes can be trained in different directions? (Your second link is behind a paywall, for me anyway.)

> I'm trying to figure out how you would even begin to do an objective study of what you're looking for since by the time kids present meaningful interests, they're already irrevocably influenced by society and their parents' expectations.

https://en.wikipedia.org/wiki/Falsifiability

What you're saying is that your hypothesis (the absence of human sexual dimorphism in brain neuroanatomy) can't be proved false by any practical experiment. Nor can the Flying Spaghetti Monster.

Imagine you lived in a world (perhaps the world of 100 years ago) in which everyone believed in human sexual dimorphism in neuroanatomy. (BTW, here's the top link I get when I google that: http://cercor.oxfordjournals.org/content/11/6/490.short). Lacking MRI scans, these uneducated people give as evidence the fact that girls prefer dolls and boys prefer tin soldiers.

Your job is to convince them otherwise. You say: my theory is that it's possible that girls prefer dolls and boys prefer tin soldiers because of thousands of years of cultural conditioning, etc. You've offered an alternative hypothesis to explain facts that both of you observe.

You haven't even begun to explain why your hypothesis should be believed over the existing null hypothesis. Your listeners ask: what evidence makes your hypothesis more plausible than mine? That genetically identical rats can be trained to do different things? What does this tell me about human sexual dimorphism?

But actually, it's not as bleak as you think. Society today has enough parents and scientists who believe in the absence of sexual dimorphism above the neck, that this experiment has not gone unperformed. One example:

https://en.wikipedia.org/wiki/John_Money#Sex_reassignment_of...