So here are some thoughts.
There was an excellent op-ed piece in the New York Times on Friday, Dec. 30, 2011. Peggy Orenstein entitled it: “Should the World of Toys be Gender-Free?”
In addition to her own work, she draws on the work of Lise Eliot, a neuroscientist, and author of “Pink Brain, Blue Brain,” among others. Orenstein recounts previous research:
Human boys and girls not only tend to play differently from one another—with girls typically clustering in pairs or trios, chatting together more than boys and playing more cooperatively—but, when given a choice, usually prefer hanging with their own kind.
Then she cites other research in looking at preschoolers, notes that
…boys from more egalitarian homes are more nurturing towards babies.
Another study shows that girls with older brothers had stronger spatial skills than both girls and boys with older sisters.
As background, I am a clinical psychologist who works with young children as well as an anthropologist. I taught child development for over thirty five years. My wife and I raised a girl and a boy. I supervised teachers in school and psychological assistants of both genders. What I have learned in terms of this is some positive warnings: boys and girls differ more within each gender than between each gender. Both our children learned to cook, sew, and do minor car repairs.
Historically, we have had Rosie the Riveter and men taking care of children. Cross-culturally, men and women have various roles, skills, and toys. My best advice is to let your child find out what s/he enjoys without any pressure. Children should be presented with a variety of toys and challenges at all ages and find their own way in play.