A child's earliest exposure to what it means to be male or female comes from parents (Lauer & Lauer, 1994; Santrock, 1994; Kaplan, 1991). From the time their children are babies, parents treat sons and daughters differently, dressing infants in gender specific colors, giving gender differentiated toys, and expecting different behavior from boys and girls (Thorne, 1993). One study indicates that parents have differential expectations of sons and daughters as early as 24 hours after birth (Rubin, Provenzano, & Luria, 1974).

Children internalize parental messages regarding gender at an early age, with awareness of adult sex role differences being found in two-year-old children (Weinraub, Clemens, Sachloff, Ethridge, Gracely, & Myers, 1984). One study found that children at two and a half years of age use gender stereotypes in negotiating their world and are likely to generalize gender stereotypes to a variety of activities, objects, and occupations (Fagot, Leinbach, & O'Boyle, 1992; Cowan & Hoffman, 1986). Children even deny the reality of what they are seeing when it doesn't conform to their gender expectations (i.e., a child whose mother is a doctor stating that only men are doctors) (Sheldon, 1990).

Sons have a definite edge as far as parental preference for children is concerned. Most parents prefer male children to female children throughout the world (Steinbacher & Holmes in Basow, 1992, p. 129). Also, people who prefer sons are more likely to use technology for selecting the sex of their child (Steinbacher & Gilroy, 1990). This preference for male children is further emphasized by the finding that parents are more likely to continue having children if they have only girls than if they have only boys (Hoffman, 1977).

Early gender socialization starts at birth and it is a process of learning cultural roles according to one's sex. Right from the beginning, boys and girls are treated differently by the members of their own environment, and learn the differences between boys and girls, women and men. Parental and societal expectations from boys and girls, their selection of gender-specific toys, and/or giving gender based assignments seem to define a differentiating socialization process that can be termed as "gender socialization". There are numerous examples from varied parts of the world confirming that gender socialization is intertwined with the ethnic, cultural, and religious values of a given society. And gender socialization continues throughout the life cycle.

Gender socialization is the process by which people learn to behave in a certain way, as dictated by societal beliefs, values, attitudes and examples. Gender socialization begins as early as when a woman becomes pregnant and people start making judgments about the value of males over females. These stereotypes are perpetuated by family members, teachers and others by having different expectations for males and females.

Imagine the following scenario: a young pregnant woman is about to have her first child. When asked whether she wishes to have a girl or boy, she replies that it doesn’t matter. But, sitting next to her is an older relative who says “Oh, hopefully it will be a boy.” In small, but meaningful ways such as this, gender socialization starts even before birth.

Children start facing norms that define “masculine” and “feminine” from an early age. Boys are told not to cry, not to fear, not to be forgiving and instead to be assertive, and strong. Girls on the other hand are asked not to be demanding, to be forgiving and accommodating and “ladylike”. These gender roles and expectations have large scale ramifications. In many parts of the world, girls face discrimination in the care they receive in terms of their access to nutritious foods and health care, leading them to believe that they deserve to be treated differently than boys. The degree of gender differences observed varies in all cultures in respect to infant, toddler and young child health, nutrition, care developmental activities, education, hygiene and protection.

I don't have any children of my own, but my sister's kids are at that very interesting age where they're just starting to identify things as "for girls" or "for boys." In a few months, I suspect my nephew won't be caught dead in Cinderella's shoes, especially when he reaches the age of my 6-year-old niece, who is currently going through her pink princess phase and notably moving into the age where "everyone in my class" birthday parties start to become "girls only" birthday parties, starting a cooties and gender-based separation that will most likely remain until middle school, when hormones override cootie-based fears and long-held gender separation rules and boys are once again permitted to join parties (much to my brother-in-law's dismay).

But going through a pink princess period and engaging in gender-specific birthday celebrations and the like might not be entirely helpful, from a developmental standpoint, according to Lise Eliot, the author of Pink Brain, Blue Brain: How Small Differences Grow into Troublesome Gaps – and What We Can Do About It. As Eliot tells Helena de Bertodano of the Times of London, the brains of boys and girls aren't really that different after all; it's the social conditioning they receive that makes them pick up and internalize gender roles. "Everything is filtered through a lens of whether you believe boys and girls are hard-wired. I don't think your average person appreciates that differences in the brain can be learnt."

Eliot's work is reflected in a study recently published in Sex Roles, which surveyed 80 families and "looked at differences in the way play and caregiving were initiated verbally, and how the participants responded - also verbally - to this initiation, for mother-son, mother-daughter, father-son and father-daughter combinations," by placing toddlers in a one-on-one situation with their parents for snack-time interaction and play-time interaction. Researchers found that toddlers of both genders showed similar communication methods during snack time, but picked up on cues given by their parents during play time, as fathers tended to encourage assertive behavior while mothers encouraged cooperation and fairness. According to the authors of the study: "It would appear that children in the same family have different experiences in their play interactions with their mothers and fathers. Such differences may teach children indirect lessons about gender roles and reinforced gender typed patterns of behavior that they then carry into contexts outside of the family."

So how can parents challenge stereotypical notions of gender? Eliot suggests that it isn't as easy as giving a girl a raygun and having a boy play with My Little Pony: "Many parents have tried this, to little effect. Girls turned the trucks into families, boys played catch with the dolls, and both sexes knew there was something fishy going on." She instead suggests that parents consider buying toys such as Legos for girls, which encourage "the kind of visuospatial skill that is linked to higher mathematic achievement," and perhaps getting your son a pet, as it encourages boys to be nurturing and patient.