From the NYT:
Guys and Dolls No More? 
By ELIZABETH SWEET
IMAGINE walking into the toy department and noticing several distinct aisles. In one, you find toys packaged in dark brown and black, which include the “Inner-City Street Corner” building set and a “Little Rapper” dress-up kit. In the next aisle, the toys are all in shades of brown and include farm-worker-themed play sets and a “Hotel Housekeeper” dress.
If toys were marketed solely according to racial and ethnic stereotypes, customers would be outraged, and rightfully so.
That is pretty much how record stores -- the few remaining, such as the beloved Amoeba Records on Sunset Blvd. -- are organized.
Yet every day, people encounter toy departments that are rigidly segregated — not by race, but by gender. There are pink aisles, where toys revolve around beauty and domesticity, and blue aisles filled with toys related to building, action and aggression.
Gender has always played a role in the world of toys. What’s surprising is that over the last generation, the gender segregation and stereotyping of toys have grown to unprecedented levels. We’ve made great strides toward gender equity over the past 50 years, but the world of toys looks a lot more like 1952 than 2012.
Gender was remarkably absent from the toy ads at the turn of the 20th century
Because children mostly got lumps of coal in their stockings. Seriously, poor societies tend to be less sex-differentiated in many ways than rich societies simply because they are poor.
It's pretty much basic Maslow Hierarchy of Needs, with survival at the bottom and self-actualization at the top. In 1900, a nice Christmas present to find in your stocking was an orange. You and your sister both liked the oranges your aunt brought you in 1897 and you've been dreaming ever since about having another orange. Their sweetness showed they were providing needed calories. Oranges even had vitamins.
A century later, you and your sister have, to be frank, more calories than you really need, but their is no end to your feeling that you need more self-actualization via fantasy, so your sister is demanding a Polly Pocket Fairy Wishing World, while you are throwing a tantrum over how much you want a Power Rangers Samurai Bull Megazord Action Figure.
but played a much more prominent role in toy marketing during the pre- and post-World War II years. However, by the early 1970s, the split between “boys’ toys” and “girls’ toys” seemed to be eroding.
In other words, feminism came to quickly dominate thinking in America after its break out in 1969.
During my research into the role of gender in Sears catalog toy advertisements over the 20th century, I found that in 1975, very few toys were explicitly marketed according to gender, and nearly 70 percent showed no markings of gender whatsoever. In the 1970s, toy ads often defied gender stereotypes by showing girls building and playing airplane captain, and boys cooking in the kitchen.
One thing you can't say about feminism is that it hasn't failed because it's never been tried.
It has been tried.
But by 1995, the gendered advertising of toys had crept back to midcentury levels, and it’s even more extreme today. In fact, finding a toy that is not marketed either explicitly or subtly (through use of color, for example) by gender has become incredibly difficult.
There are several reasons gender-based marketing has become so prevalent. On a practical level, toy makers know that by segmenting the market into narrow demographic groups, they can sell more versions of the same toy.
Boy and Girl are not exactly narrow segments.
Anyway, this doesn't make economic sense. All else being equal, manufacturers don't want to sell more versions of the same thing, they want to sell fewer versions to keep costs down: "You can have your Model T in any color you like, so long as it's black." They provide more versions because of demand: i.e., boys and girls tend to like different stuff. Just as General Motors outmarketed Ford in the 1920s because Alfred P. Sloan figured out that the country was getting prosperous enough that there was a new mass market not just for the basic transportation Ford's Model T provided, but for allowing customers to self-actualize through car purchases by providing a variety of levels of luxury in cars in multiple colors and with changing fashions in sheet metal, richer societies sell more ostentatiously masculine and feminine toys and entertainment.
And nostalgia often drives parents and grandparents to give toys they remember from their own childhood.
How does that make sense? You just said that toys were degenderized in 1975. Surely today's parents must be nostalgic for the Pat the Androgynous Action Doll that their aunt bought them at the womyn's co-op in 1975?
Oh, wait, you mean nobody remembers the neutered toys from this brief consciousness-raised phase fondly? Now why would that be?
Such marketing taps into the deeply held beliefs about gender that still operate in our culture; many parents argue that their daughters and sons like different things.
If only parents would listen to Elizabeth Sweet instead of their children about what toys their children really want.
But if parents are susceptible to the marketers’ message, their children are even more so. In a study on parental toy purchases led by the psychologist Donna Fisher-Thompson, researchers who interviewed parents leaving a toy store found that many bought gender-typed toys because their kids had asked for them, and parents were a bit less likely to choose gendered toys — at least for girls — on their own.
Moreover, expert opinion — including research by developmental and evolutionary psychologists — has fueled the development and marketing of gender-based toys. Over the past 20 years, there has been a growth of “brain science” research, which uses neuroimaging technology to try to explain how biological sex differences cause social phenomena like gendered toy preference.
That’s ridiculous, of course: it’s impossible to neatly disentangle the biological from the social, given that children are born into a culture laden with gender messages. But that hasn’t deterred marketers from embracing such research and even mimicking it with their own well-funded studies.
For example, last year the Lego Group, after two decades of marketing almost exclusively to boys, introduced the new “Friends” line for girls after extensive market research convinced the company that boys and girls have distinctive, sex-differentiated play needs.
Critics pointed out that the girls’ sets are more about beauty, domesticity and nurturing than building — undermining the creative, constructive value that parents and children alike place in the toys. Nevertheless, Lego has claimed victory, stating that the line has been twice as successful as the company anticipated.
The ideas about gender roles embedded in toys and marketing reflect how little our beliefs have changed over time, even though they contradict modern reality: over 70 percent of mothers are in the labor force, and in most families domestic responsibilities are shared more equitably than ever before. In an era of increasingly diverse family structures, these ideas push us back toward a more unequal past.
Elizabeth Sweet is a doctoral candidate in sociology at the University of California, Davis.
There are two orthogonal dimensions when it comes to how sex roles change as societies get richer, more technologically advanced, and more complex. The first is toward more flexibility because society can afford more flexibility and can exploit it more.
The second, however, is toward more self-actualization, especially in fantasy / entertainment, which is a growing segment of the economy because we can afford more. And the great majority of people want to self-actualize along the lines of their sex.
Consider explosions in movies. They used to be rather rare and perfunctory. Jimmy Cagney's "Top of the world, ma!" speech  in 1949's White Heat had a huge impact because it was followed by an early example of the kind of fireball explosion that is standard today, as parodied  [link fixed] in this year's 21 Jump Street.