User:Agrewal246/Sex differences in psychology

Schizophrenia
Main article: Sex differences in schizophrenia

Women and men are both equally likely at developing symptoms of schizophrenia, but the onset occurs earlier for men. It has been suggested that sexually dimorphic brain anatomy, the differential effects of estrogens and androgens, and the heavy exposure of male adolescents to alcohol and other toxic substances can lead to this earlier onset in men. It is believed that estrogens have a protective effect against the symptoms of schizophrenia. Although, it has been shown that other factors can contribute to the delayed onset and symptoms in women, estrogens have a large effect, as can be seen during a pregnancy. In pregnancy, estrogen levels are rising in women, so women who have had recurrent acute episodes of schizophrenia did not usually break down. However, after pregnancy, when estrogen levels have dropped, women tend to suffer from postpartum psychoses. Also, psychotic symptoms are exacerbated when, during the menstrual cycle, estrogen levels are at their lowest. ' Various neurodevelopmental theories suggest the reasoning behind an earlier onset for men. One theory suggests that male fetal brains are more vulnerable to prenatal complications. Another theory argues that the gender differentiation in schizophrenia onset is due to excessive pruning of synaptic nerves during male adolescence. "The estrogen hypothesis" proposes that higher levels of estrogen in women has a protective effect against these prenatal and adolescent complications that may be associated with men having schizophrenia onset earlier. Estrogen can alter post-synaptic signal transduction and inhibit psychotic symptoms. Thus, as women experience lower levels of estrogen during menopause or the menstrual cycle, they can experience greater amounts of psychotic symptoms. ' In addition, estrogen treatment has yielded beneficial effects in patients with schizophrenia.

Biological
Further information: Sexual differentiation in humans

Biological differentiation is a fundamental part of human reproduction. Generally, males have two different sex chromosomes, an X and a Y; females have two X chromosomes. The Y chromosome, or more precisely the SRY gene located on it, is what generally determines sexual differentiation. If a Y chromosome with a n  SRY gene is present, growth is along male lines; it results in the production of testes, which in turn produce s  testosterone. In addition to physical effects, this prenatal testosterone increases the likeliness of certain "male" patterns of behavior after birth, though the exact impact and mechanism are not well understood. Parts of the SRY and specific parts of the Y chromosome may also possibly influence different gender behaviors, but if so, these impacts have not yet been identified.

Biological perspectives on psychological differentiation often place parallels to the physical nature of sexual differentiation. These parallels include genetic and hormonal factors that create different individuals, with the main difference being the reproductive function. The brain controls  the  behavior of individuals, but it is influenced by genes, hormones, and evolution. Evidence has shown that the ways that male and female children become adults is  are  different and that there are variations between the individuals of each sex.

Sex Linkage

Certain psychological traits may be related to the chromosomal sex of the individual. In contrast, there are also "sex-influenced" (or sex-conditioned) traits, in which the same gene may present different phenotypes depending on sex. Even in a homozygous dominant or recessive female the condition may not be expressed fully.[citation needed] "Sex-limited" traits are characteristics only expressed in one sex. They may be caused by genes on either autosomal or sex chromosomes.

Evidence exists that there are sex-linked differences between the male and female brain.

' The sex differences in psychological traits may be related to sex-linked genes, genes found on the X and Y sex chromosomes.   These genes encoded on sex chromosomes have been found to influence sex-specific trait development, sexual dimorphism, neural development, and sex-specific behaviors.   The expression of sex-linked genes can result in varying effects between the sexes on the functions of the targeted cells from locally producing a hormone or messenger molecule.   Research has also reported that the expression of sex-specific genes can regulate the expression of autosomal or non-sex genes and influence phenotypic effects. This can be seen through genes linked to the X chromosome being more dominant in males, especially recessive genes, due to males having one X chromosome and one Y chromosome compared to females who have two X chromosomes.   Males are reliant on one X chromosome for the expression of sex-related genes. Genes linked to the X chromosome are further favored when Y chromosomes often being degenerate or possibly absent is considered.   It has also been found that an excessive amount of sex-related and developmental-related genes have been found on the X chromosome, thus resulting in the phenomenon of "the large X-chromosome effect." The effect of the X chromosome has been shown to be related to differences in cognitive ability between the sexes.   Research has suggested that sex differences in the brain can be attributed to the expression of sex-specific genes in the brain. '

Epigenetics
Epigenetic changes have also been found to cause sex-based differentiation in the brain. The extent and nature of these differences are not fully characterised. Differences in socialization of males and females may decrease or increase the size of sex differences.

' The expression of genes and resulting sex differences is further complicated through environmental interactions. Environmental factors can range from ecological to cultural to social.   Epigenetics refers to the study of how the environment influences biological processes that determine whether certain genes are activated or expressed.   Epigenetics plays a role in the inactivation of one of the two X chromosome in females.   The inactivation of one of the X chromosomes during early development leads to sex differences. Epigenetics can also lead to sex differences through genetic imprinting.   Imprinting involves the suppression of genes on the chromosomes inherited from the mother or father which causes for the offspring to express the inherited genes differently and have varying phenotypic effects.   Prenatal care and maternal behavior can also be environmental factors that can manifest into epigenetic modifications that impact gene expression and promote sex differences. '

Neuroscience
Main article: Neuroscience of sex differences

See also: Sex differences in human physiology § Brain and nervous system

A 2021 meta-synthesis of existing literature found that sex accounted for 1% of the brain's structure or laterality, finding large group-level differences only in total brain volume. This partially contradicts a review from 2006 and a meta-analysis from 2014 which found that some evidence from brain morphology and function studies indicates that male and female brains cannot always be assumed to be identical from either a structural or functional perspective, and some brain structures are sexually dimorphic. ' Male brains have shown to have greater matter volume in areas such as the hippocampus, amygdala, and insula which have been associated with psychological conditions that have a higher prevalence of  in males including autism and schizophrenia.   Conversely, another meta-analysis suggests that sex differences within brains should analyzed through influential factors that change and influence the sex differences such as the female menstrual cycles rather than through the biological lens of sex. '

Evolutionary product Theory
Donald Symons has argued that fundamental sex differences in genetics, hormones and brain structure and function may manifest as distal cultural phenomena (e.g., males as primary combatants in warfare, the primarily female readership of romance novels, etc.). There has been significant feminist critique of these and other evolutionary psychology arguments, from both within and outside of the scientific community.

 According to evolutionary psychology, sex differences exist due to men and women adapting to different challenges of survival in the past.   Women struggled against issues of pregnancy, birthing offspring, and child care and men faced unique issues of mating and paternity uncertainty, being uncertain if a child was their biological offspring.  ' To compete with other men for access to mates, men have evolved to have qualities of physical strength, larger body compositions, and aggressiveness. These traits allow men to occupy higher social status and have greater to mate and reproduce.   The parental investment theory also displays how sex differences have evolved. The theory suggests that members of a species that are more involved and invested in raising and birthing offspring will be more selective in choosing mates.   Thus, women have evolved to have a preference to mate with men of higher social status and with greater amounts of resources to support their offspring.   Due to such unique problems, men and women have evolved differently and display varying behaviors and psychological traits. Evolutionary psychology is a controversial perspective and criticized by other psychology theorists such as feminist psychologists for promoting gender inequality with men as dominant and women as dependent. '

Instructor feedback:

''I have included several suggested edits above for your consideration. I would suggest that you delete the second sentence you added since this can be inferred from the previous sentence. You have included two citations and both are appropriate, peer-reviewed examples of secondary literature. There are red warnings, so I think you will want to confirm your references are formatted properly. The Ruigrok et al., citation does appear to be older and I would encourage you to see if there is anything more recent. I do wonder if your final sentence might fit better within the sections on neurochemical differences? Were there other components to the paper beyond the menstrual cycle?''

Summarized changes and edits:

''Following the instructor's suggested edits, I removed the second sentence, and formatted the sources properly, removing the red warnings. I am aware that I have red warnings for two sources, but I am confused about how to resolve the "extra text" warning. I may need to seek the instructor's help. In terms of the Ruigrok et al. citation, I will be maintaining the source because I would argue that it is more recent especially compared to other sources within the article. The source is from 2014 which is within the past 10-year time frame and therefore, in my opinion, fairly recent, but I will continue to look for more recent sources to support the statements. The instructor and my peers, Zelki and Danielletjm2001, argued that the last sentence of the Neuroscience section should be removed and possibly added to a section regarding neurochemicals. However, I was struggling to place the statement in a different area of the article because I attempted to place it in the Biology or Schizophrenia section due to the relationship between estrogen levels, menstrual cycle, and schizophrenia, but the purpose of the sentence which refers to sex differences in the brain fits in the Neuroscience section. I will be seeking more guidance from my peers and instructor on the placement of this sentence. In terms of additional edits, I have re-wrote portions of the Schizophrenia section and added more recent sources which my peer, Zelki, noted needed improvement. My peer reviewers, Zelki and Danielletjm2001, also noted the underdeveloped and lack of sources in the Culture section which I have improved upon with multiple recent sources. I plan to further expand the section as I research. Both of my peer reviewers also noted the underdeveloped "sex linkages" section which I am conflicted about because the topic is somewhat covered in the Biology section. I am considering transforming Epigenetics and Sex Linkage into one section that refers to genetic factors in sex differences to reduce repetitiveness within the article. I was not able to see the peer review comments of Bmallery99, so I was not able to incorporate that.''