In my last blog post I discussed both the short- and long-term factors in how the name pool has diversified and far fewer babies are being given one of the standard classics. There is also the gender factor, and most of you probably know how it has gone for much of recent history: Boys are more likely to be given a "common" name than girls, and the names themselves at the top of the list change at a slower pace on the blue side as compared to the pinks. However, as recently as the decades immediately preceding the advent of the coverage of the SSA list, that factor was almost nonexistent.
In the late 19th century, we start to see the naming practices by gender diverge: The pace in fashion changes pick up and fewer girls being given the standard classics, with a lesser effect on the boy's side. We probably owe this to the wave of feminism that brought them the vote and other similar rights, with many seeing the old names as being stodgy to the old way of feminine thinking. With the exception of a period around the Depression when there was a brief distaste for some of the boy's classics, this pattern of a pronounced greater individualism with girl's names continued throughout the 20th century (we also see far fewer female "juniors" compared to before while the practice continued with males during this period). This diversion peaked around the period of the 1950s-70s, when you sometimes saw almost twice as many boys being given the top names as girls (this may also why you're more likely to have a "generation gap" with your parents over what to name a boy than a girl, while in the past the opposite was more likely).
The next wave of feminism in the '70s had somewhat of the opposite effect (reducing the magnitude but not reversing the pattern of the "gender gap") resulting in a regression of the long-term "name deflation" with an increase in the number of girls bestowed a top name (hence why so many feel Jennifer and Jessica are "burned out" while Lisa from just a decade or two before did not have the same effect). This is probably due to parents realizing that like with their son's names their daughter's names would likely need to withstand the test of how it would be perceived on a resume. The Great Name Deflation which began in the '90s had its effect first with girls, partially reversing the aforementioned effect for a brief period (that's when we saw the "gender crossover" with names picking up steam and more "modern" names at the top of the girl's list).
However, over the past 10-15 years we have really begun to see a pickup in the diversification of what we name our sons. Although there is still some sexism, the acceptance towards more unusual and/or unisex names for boys has softened. We are also seeing the pace in fashion changes picking up with boys, with many of the old standard classics falling and more trendy names reaching the top of the charts (in fact there are now more "non-traditional" names on the boy's Top 10 than the girls!). Another reversal of the conventional wisdom is that the top names now often rack in as much if not more usage on the girl's side (e.g. in 2011 and 2012 there were more girls named Sophia than boys named Jacob, and the same thing for the two years before that substituting Isabella for Sophia); for most of the past century it was the other way around (e.g. you probably grew up knowing more Michaels than Jennifers, although for a brief period early in the baby-boom years Linda topped Robert in usage). Is this a sign of true gender equality in the near future?