Rodent of the Week: Having a bunch of sisters might make you less sexy

Pity the poor boy--in the United States at least--wedged in the midst of a bevy of sisters. When he's little, he'll certainly be dressed and made up like a doll. He will doubtless spend time cooling his heels at the bathroom door. He'll likely pine for the attention of his sisters' girlfriends. But a new study confirms what many such boys learned long ago: that as a sexual prospect, the kid brother is chopped liver. If he's a rat, at least. "Does family play a role in shaping the adult phenotype?" asks psychobiologist David Crews and colleagues in a study published this week in the journal Psychological Science....