Tiere und Werbung mit Marken („Sex sells“)

Advertisements

Geschlechterunterschiede im Gehirn sind bereits im Alter von einem Monat vorhanden

Ein interessante Studie zu Geschlechterunterschieden im Gehirn bei Säuglingen:

The developing brain undergoes systematic changes that occur at successive stages of maturation. Deviations from the typical neurodevelopmental trajectory are hypothesized to underlie many early childhood disorders; thus, characterizing the earliest patterns of normative brain development is essential. Recent neuroimaging research provides insight into brain structure during late childhood and adolescence; however, few studies have examined the infant brain, particularly in infants under 3 months of age. Using high-resolution structural MRI, we measured subcortical gray and white matter brain volumes in a cohort (N = 143) of 1-month infants and examined characteristics of these volumetric measures throughout this early period of neurodevelopment. We show that brain volumes undergo age-related changes during the first month of life, with the corresponding patterns of regional asymmetry and sexual dimorphism. Specifically, males have larger total brain volume and volumes differ by sex in regionally specific brain regions, after correcting for total brain volume. Consistent with findings from studies of later childhood and adolescence, subcortical regions appear more rightward asymmetric. Neither sex differences nor regional asymmetries changed with gestation-corrected age. Our results complement a growing body of work investigating the earliest neurobiological changes associated with development and suggest that asymmetry and sexual dimorphism are present at birth.

Quelle: Investigation of brain structure in the 1-month infant (Scihub Volltext Link)

Aus der Studie:

Unterschiede Gehirn Mann Frau 1 Monat

Unterschiede Gehirn Mann Frau 1 Monat

Da geht es um die

  1. Größe des Gehirns von männlichen und weiblichen Babies nach Geburt.
  2. Das Volumen der weißen Substanz im Gehirn
  3. Das Volumen der grauen Substanz im Gehirn

Wie man sieht ist das Gehirn der männlichen Babies im Durchschnitt zB größer, und zwar über die hier erfassten Alter hinweg, auch wenn es einzelne männliche Babies mit relativ kleinen und einige Mädchen mit relativ großen Gehirnvolumen gibt. Der Trend ist aber recht deutlich.

Auch die Daten zu den verschiedenen Bereichen zeigen deutliche Unterschiede:

Unterschiede Gehirn Mann Frau 1 Monat

Unterschiede Gehirn Mann Frau 1 Monat

Es wird schwer das mit einer unterschiedlichen Sozialisiation zu erklären. Sie müsste dann wohl bereits im Mutterleib ansetzen. Was allerdings pränatale Hormone in der Tat machen, wie man beispielsweise an dem Testosteronspiegel sieht:

Testosteron Maenner Frauen

Testosteron Maenner Frauen

Aus einer Besprechung der Studie:

Dean’s team found that the boys’ brains were 8.3 per cent bigger, in line with the sex difference in brain volume found in adults and the few other available infant studies. Also as seen in adults, male brains had relatively more white matter (connecting tissue) and female brains more grey matter, relative to total brain size.

A number of specific neural areas were larger in males, such as parts of the limbic system involved in emotions, including the amygdala, insula, thalamus and putamen. The researchers also found evidence for relatively larger hippocampi, an area involved in memory, which has more commonly been found to be larger in females, although not universally so. Meanwhile female brains were relatively larger in other limbic areas such as parts of the cingulate gyrus, caudate and parahippocampal gyrus, and they had a few white-matter structures that were relatively larger.

These sex differences were smaller than has been observed in adults, which suggests that maturation continues this differentiation, likely through the high volume of sex steroid receptors in these brain areas. The alternative suggestion is that the subsequent differentiation is due to socialisation, but for the forces of socialisation to work along the same lines as pre-existing biological forces would suggest that socialisation is at most a feedback loop between biology and society.

There were a lot of brain areas that differed structurally between the sexes, but it would be irresponsible to draw any firm conclusions about what they might mean for function and behaviour. For instance,  what could differences in overall insula size possibly mean psychologically when the area is associated with “compassion and empathy, perception, motor control, self-awareness, cognitive functioning”, “interpersonal experience” and “psychopathology”?

Insofern liegt noch viel Arbeit vor den Forschern, bis sie die Unterschiede wirklich verstehen. Aber dennoch entzieht diese Studie vielen, die auf einen Blank Slate abstellen und annehmen, dass Geschlechterunterschiede nur auf Sozialisiation zurück gehen können einiges an Boden bzw. erfordert, dass diese ihre Thesen kritisch hinterfragen.

Vgl auch:

Alterspräferenzen von Männern und Frauen bei der Partnerwahl

Eine interessante Studie behandelt die Altersdifferenzen bei der Partnerwahl:

The finding that women are attracted to men older than themselves whereas men are attracted to relatively younger women has been explained by social psychologists in terms of economic exchange rooted in traditional sex-role norms. An alternative evolutionary model suggests that males and females follow different reproductive strategies, and predicts a more complex relationship between gender and age preferences. In particular, males‘ preferences for relatively younger females should be minimal during early mating years, but should become more pronounced as the male gets older. Young females are expected to prefer somewhat older males during their early years and to change less as they age. We briefly review relevant theory and present results of six studies testing this prediction.

Study 1 finds support for this gender-differentiated prediction in age preferences expressed in personal advertisements.

Study 2 supports the prediction with marriage statistics from two U.S. cities.

Study 3 examines the cross- generational robustness of the phenomenon, and finds the same pattern in marriage statistics from 1923.

Study 4 replicates Study 1 using matrimonial advertisements from two European countries, and from India.

Study 5 finds a consistent pattern in marriages recorded from 1913 through 1939 on a small island in the Philippines.

Study 6 reveals the same pattern in singles advertisements placed by financially successful American women and men.

We consider the limitations of previous normative and evolutionary explanations of age preferences and discuss the advantages of expanding previous models to include the life history perspective.

Quelle: Age preferences in mates reflect sex differences in mating strategies (Abstract/Scihub)

Aus der Studie:

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

Hier sieht man, wie sich die Alterspräferenzen bei der Partnerwahl in Anzeigen unterscheiden. Gut zu sehen ist, dass Männer in jungen Jahren (in den 20igern) durchaus noch ältere Frauen interessant finden (bis zu 5 Jahren) und die Frauen auch nicht sehr viel Jünger sein sollen (5 Jahre jünger). Bereits in den 30igern wollen Männer keine älteren Frauen mehr, aber sehr gerne noch jüngere. Insgesamt passen die Interessen ganz gut zu dem Verlauf der Fruchtbarkeit, die ich hier noch einmal aus einem anderen Artikel einfüge:

Unfruchtbarkeit Frau Alter

Unfruchtbarkeit Frau Alter

Bei den Frauen sind hingegen die 20jährigen auch an 10 Jahre älteren interessiert und das ändert sich nicht viel, auch wenn sie älter werden. Sie gehen weitaus weniger als die Männer nach unten und in den 20igern und den 60igern gar nicht mehr. Meinte Vermutung wäre, dass sie in den 20igern weniger Kompromisse machen müssen und in den 60igern weniger Kompromissen machen wollen.

In der nächsten Grafiken wird dann gezeigt, wie die tatsächlichen Altersunterschiede aussahen

In Seattle 1986

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

in Phönix 1986:

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

Auch in den tatsächlichen Zahlen finden sich die entsprechenden Präferenzen wieder. Wenn Frauen in den 40igern geheiratet haben, dann Männer, die etwas älter sind, wenn Männern in den 40igern geheiratet haben, dann deutlich jünger.
Das beide Kurven das so deutlich zeigen müsste ja bedeuten, dass die Geschlechter auch in verschiedener Zahl in den verschiedenen Alterstufen heiraten.  Man darf annehmen, dass die Kombination zB 26 jährige Frau heiratet Mann Anfang 30 zB wesentlich häufiger ist als 60jähriger Mann heiratet 50jährige Frau.

Auch die nächsten zwei Grafiken sind interessant:

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

Die Abbildung 4 zeigt, dass auch ältere Statistiken sehr ähnliche Grafiken zeigen, hier aus dem Jahr 1923. Die Männer haben da eher noch jüngere Frauen mit dem älter werden bevorzugt (vermutlich weil man eher noch Kinder haben wollte und wahrscheinlich auch jüngere Frauen aufgrund der stärkeren Haltbarkeit der Ehen bessere Chancen boten).

Die Abbildung 5 zeigt dann die Alterspräferenzen für den Partner in deutschen Anzeigen. die Bilder unterscheiden sich nicht wesentlich von den USA.

Auch in den Niederlanden ist das Bild ganz ähnlich:

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

Und auch in Indien ist das Grundschema gut wiederzuerkennen:

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

Und schließlich noch von einer philipinischen Insel im Zeitraum 1913-1939

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

Auch hier zeigt sich das gleiche Muster.

Das Muster bleibt auch relativ stabil, wenn man Reiche mit armen Leuten vergleicht:

Alterspräferenzen Partnerwahl Männer Frauen

Alterspräferenzen Partnerwahl Männer Frauen

Die „Vierecke“ sind die Reichen, die Kreise die Jungen. Beide geben ungefähr die gleichen Unterschiede an, bei den Männern gehen die 60iger lediglich deutlich weiter nach unten.

Eine weitere Grafik legt dann die Präferenzen und die tatsächlichen Daten übereinander und man sieht, dass die Mittelwerte in den Präferenzen erzielt worden sind.

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

 

Es folgt dann noch eine Grafik, die die Partnerwahl von Leuten mit hohen Status mit den Heiratsalter der Leute auf Poro vergleicht. Es scheint als würde man auf Poro bei den Männern sehr nahe an dem sein, was die Reichen als untere Präferenz angeben.

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

Zuletzt enthält die Studie noch einige Angaben dazu, welche Faktoren in diese Altersunterschiede hineinspielen können:

 

Partnerwahl Alter Männer Frauen

Partnerwahl Alter Männer Frauen

vgl auch:

Schimpansen, Männer und Tötungsopfer und Täter nach Geschlecht

#4genderstudies Studien, zu denen ich gerne eine Stellungnahme von den Gender Studies hätte, wenn sie eine Wissenschaft sind

Liebe Gender Studies,

wenn ihr euren schlechten Ruf loswerden wollt und eine Wissenschaft sein wollt, dann solltet ihr euch auch kritischen Fragen stellen und Studien wahrnehmen, die euren Theorien entgegen stehen

Ich bin gespannt, wie wissenschaftlich ihr das angeht.

Vielen Dank im voraus

Christian

Hier die Studien:

Male Gender Identity and Masculine Behavior: the Role of Sex Hormones
in Brain Development

From studies in both clinical and non-clinical samples, it seems safe to infer that prenatal exposure to androgens influence certain male gender role behaviors. Not only 46,XY but also 46,XX individuals who are exposed to high levels of testosterone, exhibit behaviors that are typically attributed to males. With regard to gender identity, we cannot draw similar
conclusions with the same level of confidence.
Elevated percentages of gender dys phoria have been found in 46,XX individuals with known exposure to atypical levels of androgens, but there is not a one-to-one relationship between such exposure and gender identity problems. Also, in individuals with a gender identity that does not correspond to their natal sex, there are indications of exposure to atypical levels of sex hormones. However, these results again do not point to a one-to-one relationship between gender identity and prenatal sex hormone levels. With regard to male development, it seems likely, on the basis of the current evidence, that sex hormones, androgens in particular, lay important groundwork for gender development. Prenatal androgens result in male-appearing genitals at birth. As a result, the envi ronment
will consider the child as a boy and treat him likewise. Prenatal brain exposure to androgens also results in various male- typical behaviors. The developing boy will consider (male genitals) and label himself ( cognitive
development) as a boy, choose male models and increasingly create his own social environment. If all these factors (body/ genitals, perception of the environment, selfperception, behaviors, and preferences) work in accordance with each other and reinforce each other, there seems to be no other possible outcome in adulthood than a firmly established male gender identity and correspond ing male behavior patterns, including sexuality. However, when some of these elements work for some reason against a male pathway, it is likely that the adult will have a gender variant identity and/or show gender variant behaviors and preferences

The Distance Between Mars and Venus: Measuring Global Sex Differences in Personality

Background
Sex differences in personality are believed to be comparatively small. However, research in this area has suffered from significant methodological limitations. We advance a set of guidelines for overcoming those limitations: (a) measure personality with a higher resolution than that afforded by the Big Five; (b) estimate sex differences on latent factors; and (c) assess global sex differences with multivariate effect sizes. We then apply these guidelines to a large, representative adult sample, and obtain what is presently the best estimate of global sex differences in personality.
Methodology/Principal Findings
Personality measures were obtained from a large US sample (N = 10,261) with the 16PF Questionnaire. Multigroup latent variable modeling was used to estimate sex differences on individual personality dimensions, which were then aggregated to yield a multivariate effect size (Mahalanobis D). We found a global effect size D = 2.71, corresponding to an overlap of only 10% between the male and female distributions. Even excluding the factor showing the largest univariate ES, the global effect size was D = 1.71 (24% overlap). These are extremely large differences by psychological standards.
Significance
The idea that there are only minor differences between the personality profiles of males and females should be rejected as based on inadequate methodology.

 

Androgen and psychosexual development: Core gender identity, sexual orientation, and recalled childhood gender role behavior in women and men with congenital adrenal hyperplasia (CAH)

We assessed core gender identity, sexual orientation, and recalled childhood gender role behavior in 16 women and 9 men with congenital adrenal hyperplasia (CAH) and in 15 unaffected female and 10 unaffected male relatives, all between the ages of 18 and 44 years. Women with CAH recalled significantly more male‐typical play behavior as children than did unaffected women, whereas men with and without CAH did not differ. Women with CAH also reported significantly less satisfaction with the female sex of assignment and less heterosexual interest than did unaffected women. Again, men with CAH did not differ significantly from unaffected men in these respects. Our results for women with CAH are consistent with numerous prior reports indicating that girls with CAH show increased male‐typical play behavior. They also support the hypotheses that these women show reduced heterosexual interest and reduced satisfaction with the female sex of assignment. Our results for males are consistent with most prior reports that boys with CAH do not show a general alteration in childhood play behavior. In addition, they provide initial evidence that core gender identity and sexual orientation are unaffected in men with CAH. Finally, among women with CAH, we found that recalled male‐typical play in childhood correlated with reduced satisfaction with the female gender and reduced heterosexual interest in adulthood. Although prospective studies are needed, these results suggest that those girls with CAH who show the greatest alterations in childhood play behavior may be the most likely to develop a bisexual or homosexual orientation as adults and to be dissatisfied with the female sex of assignment.

 

Prenatal hormones and childhood sex-segregation: Playmate and play style preferences in girls with congenital adrenal hyperplasia

We investigated playmate and play style preference in children with congenital adrenal hyperplasia (CAH) (26 females, 31 males) and their unaffected siblings (26 females, 17 males) using the Playmate and Play Style Preferences Structured Interview (PPPSI). Both unaffected boys and girls preferred same-sex playmates and sex-typical play styles. In the conflict condition where children chose between a same-sex playmate engaged in an other-sex activity or an other-sex playmate engaged in a same-sex activity, boys (both CAH and unaffected brothers) almost exclusively chose playmates based on the preferred play style of the playmate as opposed to the preferred gender label of the playmate. By contrast, unaffected girls used play style and gender label about equally when choosing playmates. Girls with CAH showed a pattern similar to that of boys: their playmate selections were more masculine than unaffected girls, they preferred a boy-typical play style and, in the conflict condition, chose playmates engaged in a masculine activity. These findings suggest that prenatal androgen exposure contributes to sex differences in playmate selection observed in typically-developing children, and that, among boys and girls exposed to high levels of androgens prenatally, play style preferences drive sex segregation in play.

 

Discordant Sexual Identity in Some Genetic Males with Cloacal Exstrophy Assigned to Female Sex at Birth

Background

Cloacal exstrophy is a rare, complex defect of the entire pelvis and its contents that occurs during embryogenesis and is associated with severe phallic inadequacy or phallic absence in genetic males. For about 25 years, neonatal assignment to female sex has been advocated for affected males to overcome the issue of phallic inadequacy, but data on outcome remain sparse.

Methods

We assessed all 16 genetic males in our cloacal-exstrophy clinic at the ages of 5 to 16 years. Fourteen underwent neonatal assignment to female sex socially, legally, and surgically; the parents of the remaining two refused to do so. Detailed questionnaires extensively evaluated the development of sexual role and identity, as defined by the subjects‘ persistent declarations of their sex.

Results

Eight of the 14 subjects assigned to female sex declared themselves male during the course of this study, whereas the 2 raised as males remained male. Subjects could be grouped according to their stated sexual identity. Five subjects were living as females; three were living with unclear sexual identity, although two of the three had declared themselves male; and eight were living as males, six of whom had reassigned themselves to male sex. All 16 subjects had moderate-to-marked interests and attitudes that were considered typical of males.Follow-up ranged from 34 to 98 months.

Conclusions

Routine neonatal assignment of genetic males to female sex because of severe phallic inadequacy can result in unpredictable sexual identification. Clinical interventions in such children should be reexamined in the light of these findings.

Biological limits of gender construction.

A biosocial theory of gender is constructed on both the macro and micro levels. A micro-model of within-sex differences among females integrates the biological model current in primatology with the prevailing social science model. It shows how sex differences in hormone experience from gestation to adulthood shape gendered behavior (that is, behavior that differs by sex). On the macro level, this model also illustrates how socialization and environment shape gendered behavior. It then demonstrates how hormone experiences can facilitate or dampen the effects of socialization and environment on gendered behavior. Data were analyzed from a sample of 163 White women who were studied from before they were born to the end of their 3rd decade. Results show that prenatal androgen exposures from the 2nd trimester affected gendered behavior, but not exposures from the 1st or 3rd trimesters. Further, the basic hormone model shows that in this sample, mothers‘ prenatal hormones had an effect on the gendered behavior of the Ss 3 decades later. The author speculates about the constraints placed by biology on the social reconstruction of gender.

Men and Things, Women and People: A Meta-Analysis of Sex Differences in Interests

The magnitude and variability of sex differences in vocational interests were examined in the present meta-analysis for Holland’s (1959, 1997) categories (Realistic, Investigative, Artistic, Social, Enterprising, and Conventional), Prediger’s (1982) Things–People and Data–Ideas dimensions, and the STEM (science, technology, engineering, and mathematics) interest areas. Technical manuals for 47 interest inventories were used, yielding 503,188 respondents. Results showed that men prefer working with things and women prefer working with people, producing a large effect size (d 0.93) on the Things–People dimension. Men showed stronger Realistic (d 0.84) and Investigative (d 0.26) interests, and women showed stronger Artistic (d 0.35), Social (d 0.68), and Conventional (d 0.33) interests. Sex differences favoring men were also found for more specific measures of engineering (d 1.11), science (d 0.36), and mathematics (d 0.34) interests. Average effect sizes varied across interest inventories, ranging from 0.08 to 0.79. The quality of interest inventories, based on professional reputation, was not differentially related to the magnitude of sex differences. Moderators of the effect sizes included interest inventory item development strategy, scoring method, theoretical framework, and sample variables of age and cohort. Application of some item development strategies can substantially reduce sex differences. The present study suggests that interests may play a critical role in gendered occupational choices and gender disparity in the STEM fields.

Und noch ein paar nur als Links:

(Aus diesem Video)

Sex differences in personality/cognition:
Lynn (1996): http://bit.ly/2vThoy8
Lippa (2008): http://bit.ly/2vmtSMs
Lippa (2010): http://bit.ly/2fBVn0G
Weisberg (2011): http://bit.ly/2gJVmEp
Del Giudice (2012): http://bit.ly/2vEKTUx

Larger/large and stable sex differences in more gender-neutral countries: (These findings run precisely contrary to social constructionist theory: it’s been tested, and it’s wrong).

Katz-Gerrog (2000): http://bit.ly/2uoY9c4
Costa (2001): http://bit.ly/2utaTT3
Schmitt (2008): http://bit.ly/2p6nHYY
Schmitt (2016): http://bit.ly/2wMN45j

Differences in men and women’s interest/priorities:
Lippa (1998): http://bit.ly/2vr0PHF
Rong Su (2009): http://bit.ly/2wtlbzU
Lippa (2010): http://bit.ly/2wyfW23
See also Geary (2017) blog: http://bit.ly/2vXqCcF

Life paths of mathematically gifted females and males:
Lubinski (2014): http://bit.ly/2vSjSxb

Sex differences in academic achievement unrelated to political, economic, or social equality:
Stoet (2015): http://bit.ly/1EAfqOt

Big Five trait agreeableness and (lower) income (including for men):
Spurk (2010): http://bit.ly/2vu1x6E
Judge (2012): http://bit.ly/2uxhwQh

The general importance of exposure to sex-linked steroids on fetal and then lifetime development:
Hines (2015) http://bit.ly/2uufOiv

Exposure to prenatal testosterone and interest in things or people (even when the exposure is among females):
Berenbaum (1992): http://bit.ly/2uKxpSQ
Beltz (2011): http://bit.ly/2hPXC1c
Baron-Cohen (2014): http://bit.ly/2vn4KXq
Hines (2016): http://bit.ly/2hPYKSu

Primarily biological basis of personality sex differences:
Lippa (2008): http://bit.ly/2vmtSMs
Ngun (2010): http://bit.ly/2vJ6QSh

Status and sex: males and females
Perusse (1993): http://bit.ly/2uoIOw8
Perusse (1994): http://bit.ly/2vNzcL6
Buss (2008): http://bit.ly/2uumv4g
de Bruyn (2012): http://bit.ly/2uoWkMh

Personality and political belief:
Gerber (2010): http://bit.ly/2hOpnHa
Hirsh (2010): http://bit.ly/2fsxIzB
Gerber (2011): http://bit.ly/2hJ1Kjb
Xu (2013): http://bit.ly/2ftDhOq
Burton (2015): http://bit.ly/2uoPS87
Bakker (2016): http://bit.ly/2vMlQ1N

Occupations by gender:
http://bit.ly/2vTdgPp

Problems with the measurement and concept of unconscious bias:
Fielder (2006): http://bit.ly/2vGzhQP
Blanton (2009): http://bit.ly/2vQuwEP (this one is particularly damning)

Microaggressions: Strong claims, weak evidence:
Lilienfeld (2017): http://bit.ly/2vS28lg

 

Geschlechterdifferenzen bei Verletzungsspuren an prehistorischen Skeletten

Attraktivität der Frauen und ihre Reproduktionsrate