Introduction
Over the years, psychologists have examined the extent at which gender identities, behaviors, and roles are influenced by nature and nurture. Most studies have tried to unravel the reason behind occurrences such as similar-sex friendships, physical aggressiveness in males, and differences in toy preferences between males and females. According to Pastorino & Doyle-Portillo (2011), such dissimilarities are as a result of sexual identities being influenced by hormonal differences between males and females. On the other hand, nurture plays a role since a child’s environment contains messages and tools for parents, teachers, and peers regarding gender and they act as powerful influences of nurture when it comes to gender behaviors.
Biological Factors
When it comes to sexual differentiation, it is considered that the human embryo does not have external tissues that can build up to either male or female during the undifferentiated phase of development (Pastorino & Doyle-Portillo, 2011). Accordingly, when chemical H-Y antigen are present, the fetus develops into a male, and when the H-Y antigen is absent, the fetus develops into a female (Swerdloff, Wang, & Hikim, 2010). The relative lack of male sex hormones results in the development of the females internal and external organs while suppressing the formation of male internal makeup. Thus, gender is defined biologically before a person is born and hormones together with the lateralization of individual brain functions affect gender distinctions. The hormones facilitate sexual-organ differentiation in-utero and this later on sets off puberty that plays a crucial role in forming gender identity.
Consequently, puberty triggers propensity towards a certain gender, which is manifested through attractions to the opposite sex. The amount of androgen during gestation, especially testosterone, establishes whether a fetus will develop into either a male or a female offspring. Several studies also suggest that androgen levels can result in the brain to be structured differently thus generating behavioral differences afterwards (Swerdloff, Wang, & Hikim, 2010). Even though both males and females do possess androgens, estrogens, or progestin, their levels are quite different. That is why, high levels of androgens in females or high levels of estrogens in males can result in some measure of hermaphrodism (Bursztyn, 2011).
Furthermore, the level of gestational hormone in both males and females only accounts for roughly a quarter of dissimilarities when it comes to gendered behavior. Such sexual distinctions have been reported in the studies contained in Hetherington & Parke (2002) that applied brain imaging to observe blood flow. The observations of these studies revealed that superior bilateralism takes place more in females than males. Additionally, by applying rhyming words, there occurred an activation of the left and right phases in the brain in females. However, in males, only the left hemisphere became activated. Thus, the male brain is structured to mirror greater lateralization, an identity that has been linked to their success in spatial functions. Therefore, when females are exposed to unusually high amounts of androgens at some point during gestation, they display greater awareness in physical activities (Hetherington & Parke, 2002).
The release of the growth hormones at some point in puberty shapes complex and discernible hormonal plus bodily sexual differentiation. Therefore, males develop their facial and body hairs, deeper voices, and increased growth of their penises and testicles. On the other hand, females start to develop their body hair while their hips broaden with the beginning of menstruation (Bursztyn, 2011). However, hormonal errors can result in a person to have both male and female sexual organs. The most common one being pseudo-hermaphrodite, whereby an individual has an indefinite internal and external sexual anatomy due to prenatal hormonal faults. For instance, a genetic female can develop ovaries and enlarged clitoris that are similar to a minuscule penis (Pastorino & Doyle-Portillo, 2011).
Environmental Influences
Given the fact that gender is not identified as a collection of traits or roles but instead as an outcome of social goings, it is maintained and reinforced via daily basis interactions together with social performance (Hetherington & Parke, 2002). From an early age, children build up stereotypical conceptions regarding both genders and as a result, they begin to apply such conceptions to categorize their awareness and behavior. Children are constantly urged to behave based on conventional gender norms. Hence, most parents will handle their girls as delicate but beautiful and encourage their boys to behave in a masculine manner. People learn appropriate behaviors through their parents, the media, their peers, as well as other fronts of socialization. However, from studies that have been conducted, it has been identified that the family has the greatest outcome of a child’s gender identity (Swerdloff, Wang, & Hikim, 2010).
From birth, children are regularly dressed in gender precise clothing and subsequently handled based on their gender as they grow (Swerdloff, Wang, & Hikim, 2010). For instance, across most cultures, boys are handled based on parental power while girls are protected. Thus, a father asserts the girl’s feminism, through enforcing of her feminine role as she takes notice of his masculinity. Therefore, lack of a father or mother can easily disturb gender typing for pre-teens, especially their relationships with the opposite sex. Other social factors such as fairy tales, the television, and art display stereotypical gender roles that serve to enforce traditional gender identities and responsibilities in shaping children’s gender decisions (Hetherington & Parke, 2002).
Biopsychology View
When it comes to nature-nurture role in shaping gender identities, bio-psychologists do have an interactionist viewpoint. The argument is that a combination of biological predisposition together with environmental factors shape gender identities in an individual (Pastorino & Doyle-Portillo, 2011). Social influences also play a significant role in gender identification. However, the biological predisposition affects nurture experiences. This concept is explained by cognitive social learning supposition and the gender-schema assumption. In particular, Kohlberg argues that children apply physical and clear behavioral evidences, to distinguish their sexual identity and gender roles (Hetherington & Parke, 2002). Hence, gender identity starts when a child develops awareness of his or her body.
Zucker & Bradley (1995) observed that gender non-conforming children become temperamentally reserved, a stand that later on brings about their gender non-conforming identities and appearance. Evidently, an investigation of gender distinctiveness of 43 genetic females who had been born with congenital adrenal-hyperplasia condition revealed that even though they behave similar to males, they still self-identify themselves as females despite the fact that they generate enough cortical hormones that results in their adrenal glands to generate excess male sex hormones (Berenbaum & Bailey, 2003). Thus, nurture, especially the way their parents handled them, affects their hormonal determinism of sexual identity.
This observation is also supported by a study done by Reiner & Gearhart (2004) on cloacal exstrophy children who during their utero had their brains being exposed to male hormones. The children identified themselves as males although their parent raised them as females. Incredibly, some of these children were born without penises, while some had smaller ones even though they all had typical male hormones, and X-Y chromosomes. This study revealed that hormonal factors during pre-natal sex differentiation are more apparent than nurturing factors in gender identification. Thus, despite fourteen of the sixteen children having undergone an early surgery to reassign their sex and then afterwards raised as females, they still displayed male characteristics such as aggressiveness in their play in addition to maintaining many male friends (Reiner & Gearhart, 2004).
Conclusion
Based on the above evaluations, biological factors have the greatest influence on gender identity than nurture. Therefore, even through sexual identity is both a biological and environmental phenomenon, most of the traits exhibited by individuals highly rely on their hormonal constitution since their brains are subjected to hormones such as testosterone during infancy. As a result, the studies that focus on sexual indentity need to put into consideration the effect that biological factors and the environment factors have on an individual during the early years of development. Notably, social factors are also essential since they interact with biological factors throughout children development course. Therefore, the genetic constitution of an individual as well as the the hormones that are present in an individual are essential in developing the biological structures of an individual and his/her general behavior. Even though nurture is important in gender identification, the argument is that biological predisposition affects the socialization experiences that shape up sexual identities.
References
Berenbaum, S. A., & Bailey, J. M. (2003). Effects on gender identity of prenatal androgens and genital appearance: Evidence from girls with congenital adrenal hyperplasia. Journal of Clinical Endocrinology and Metabolism, 88(3), 1102-1106.
Bursztyn, A. (2011). Childhood Psychological Disorders: Current Controversies. Boston: ABC-CLIO.
Hetherington, M., & Parke, R. (2002). Child Psychology: A Contemporary Viewpoint. New York: McGraw-Hill.
Pastorino, E. E., & Doyle-Portillo, S. M. (2011). What Is Psychology? Los Angeles: Cengage Learning.
Reiner, W. G., & Gearhart, J. P. (2004). Discordant sexual identity in some genetic males with cloacal exstrophy assigned to female sex at birth. The New England Journal of Medicine , 350(4), 333-341.
Swerdloff, R. S., Wang, C., & Hikim, A. P. (2010). Hormones, Brain and Behavior, Five-Volume Set. New York: Academic Press.
Zucker, K. J., & Bradley, S. J. (1995). Gender Identity Disorder and Psychosexual Problems in Children and Adolescents. Guilford Press.