Sociologists and other social scientists generally attribute many of the behavioral differences between genders to socialization. Socialization is the process of transferring norms, values, beliefs, and behaviors to group members. The most intense period of socialization is during childhood, when adults who are members of a particular cultural group instruct young children on how to behave in order to comply with social norms. Gender is included in this process; individuals are taught how to socially behave in accordance with their assigned gender, which is assigned at birth based on their biological sex (for instance, male babies are given the gender of "boy", while female babies are given the gender of "girl"). Gender socialization is thus the process of educating and instructing males and females as to the norms, behaviors, values, and beliefs of group membership .
Preparations for gender socialization begin even before the birth of the child. One of the first questions people ask of expectant parents is the sex of the child. This is the beginning of a social categorization process that continues throughout life. Preparations for the birth often take the infant's sex into consideration (e.g., painting the room blue if the child is a boy, pink for a girl). Today it is largely believed that most gender differences are attributed to differences in socialization, rather than genetic and biological factors.
Gender stereotypes can be a result of gender socialization. Girls and boys are expected to act in certain ways, and these ways are socialized from birth by many parents (and society). For example, girls are expected to be clean and quiet, while boys are messy and loud. As children get older, gender stereotypes become more apparent in styles of dress and choice of leisure activities. Boys and girls who do not conform to gender stereotypes are usually ostracized by same-age peers for being different. This can lead to negative effects, such as lower self-esteem.
In Western contexts, gender socialization operates as a binary, or a concept that is exclusively comprised of two parts. In other words, individuals are socialized into conceiving of their gender as either masculine (male) or feminine (female). Identities are therefore normatively constructed along this single parameter. However, some individuals do not feel that they fall into the gender binary and they choose to question or challenge the male-masculine / female-feminine binary. For example, individuals that identify as transgender feel that their gender identity does not match their biological sex. Individuals that identify as genderqueer challenge classifications of masculine and feminine, and may identify as somewhere other than male and female, in between male and female, a combination of male and female, or a third (or forth, or fifth, etc.) gender altogether. These identities demonstrate the fluidity of gender, which is so frequently thought to be biological and immutable. Gender fluidity also shows how gender norms are learned and either accepted or rejected by the socialized individual.