Is this a hobby or activity?

So I was listening to Sampler this morning, and they played a clip from Slate’s Double X that was discussing David Brook’s NYT piece about why HRC is disliked. In it, he kind of implies it’s because she’s a no fun having workhorse without hobbies. Then he goes on to list Obama’s hobbies as, “golf, basketball, etc.”

So what’s considered a hobby? She’s mentioned she likes shopping, yoga, and reading interior design things. I mentioned it to dude coworker and he brought up that the things we view as hobbies mostly skew masculine: sports, beer brewing, etc. Whereas things that skew feminine tend to be seen as “activities”: shopping, reading magazines, etc. But why? Is there a development aspect that makes it inherently a hobby as opposed to an activity? I watch documentaries, is that a hobby or an activity? What’s your definition?

Katy Waldman has a good piece that goes deeper into this, I highly recommend it.