The XX Factor: Slate women blog about politics, etc...

Breasts, etc.

Rachael, isn’t part of the issue that white-collar jobs tend to accommodate pumping and breastfeeding more than blue-collar or service industry jobs do? This piece, for instance, paints a stark contrast between female Starbucks execs who get to use a lovely “Lactation Room,” and women working behind café counters who have to pump in bathrooms during quickie breaks. Anything that makes it easier for women to pump at work (or during their medical boards!) seems like a good idea to me – and not paternalistic.

Meanwhile, speaking of Emily’s great piece, I wanted to mention another mind-bending example of how environment can influence gene expression. This one comes from a UC Davis psychologist named Brian Trainor, who’s done fascinating work on the relationship between estrogen and aggressive behavior in mice. Last year, Trainor found that estrogen can have completely opposite effects on aggression depending on the length of daylight. Specifically, the hormone made mice less aggressive when daylight hours were kept long, simulating summer. But it made them more aggressive when daylight hours were short, simulating winter. (The pathways involved were probably different, too.) No one knows whether similar effects will be found in humans. But isn’t it wild to imagine estrogen making us docile in summer and assertive in winter, too?