Not really, if your wife isn't transgender, your claims of her feelings are irrelevant -- and the fact that you attempt to correlate lower testosterone levels in a cis woman with "bit less girly then other females" and claims of lacking maternal instinct, is frankly ridiculous.

They are not the same.

No, one is a form of natural experiment (changing the hormone profile of a single person who can compare the causal effects).

The other is an assumption that someone's observed characteristics are caused by one particular hormone level, with no evidence to support that.

You could attribute her height and preference for fatty fish to her T levels too, if you strained hard enough.

> No, one is a form of natural experiment (changing the hormone profile of a single person who can compare the causal effects).

But this is subject to placebo effect, as the OP said, so you can't directly infer a casual influence on behaviour.

> The other is an assumption that someone's observed characteristics are caused by one particular hormone level, with no evidence to support that.

The OP did not say the lack of maternal instincts was caused by lower than normal testosterone, they simply noted that she had both characteristics.

It's not a very well-designed experiment. Aside from changing hormone levels, there's a slew of other variables: Relief at having achieved their transition, aging and maturation, actual memory of past feelings and experiences, and so on. Further, simply using one's self-reported perceptions doesn't provide a very secure footing for a serious result. Sure, use it to drive curiosity and do further experiments. But don't believe your deriving too much "truth" at this point.