Gründe für Geschlechterunterschiede in STEM: Unterschiede in Präferenzen und Prioritäten (Teil 1)

Eine interessante Studie bespricht eine Vielzahl von Gründen, warum sich Geschlechterunterschiede im STEM-Bereich ergeben.

It is a well-known and widely lamented fact that men outnumber women in a number of fields in STEM (science, technology, engineering and maths). The most commonly discussed explanations for the gender gaps are discrimination and socialization, and the most common policy prescriptions target those ostensible causes. However, a great deal of evidence in the behavioural sciences suggests that discrimination and socialization are only part of the story. The purpose of this paper is to highlight other aspects of the story: aspects that are commonly overlooked or downplayed. More precisely, the paper has two main aims. The first is to examine the evidence that factors other than workplace discrimination contribute to the gender gaps in STEM. These include relatively large average sex differences in career and lifestyle preferences, and relatively small average differences in cognitive aptitudes – some favouring males, others favouring females – which are associated with progressively larger differences the further above the average one looks. The second aim is to examine the evidence suggesting that these sex differences are not purely a product of social factors but also have a substantial biological (i.e. inherited) component. A more complete picture of the causes of the unequal sex ratios in STEM may productively inform policy discussions.

Quelle: Men, women and STEM: Why the differences and what should be done?

Die Einteilung in der Studie ist wie folgt:

1. Sex differences in preferences and priorities
2. Sex differences in cognitive aptitudes
3. Sex differences in variability
4. Bias and discrimination in the workplace
5. Policy implications
6. Levelling the playing field vs. equalizing sex ratios
7. Conclusion: Many factors at play

Ich dachte ich gehe diese Punkte mal einzeln durch, weil da viel interessantes dabei ist

Aus dem Text:

Sex differences in preferences and priorities

To begin with, we examine arguably the most important contributor to the differential representation of men and women in STEM: sex differences in career-relevant preferences. Specifically, we look at sex differences in interests and occupational preferences and sex differences in life priorities. Having sketched an origins-agnostic outline of these differences, we then make the case that biological factors play an important part in shaping them, and speculate about the evolutionary pressures that might have helped shape the biological contribution.

Interests and occupational preferences

A large literature in psychology shows that men and women differ, on average, in the kinds of occupations that interest them (Konrad et al., 2000; Morris, 2016). One of the most important recent papers on this topic was a comprehensive meta-analysis by Su et al. (2009). The paper focused on two main areas: occupation-relevant interests (e.g. interest in people vs. things) and preferences for specific STEM careers (e.g. engineering vs. mathematics). In both cases, the authors found substantial sex differences that, regardless of their causes, plausibly go some way towards explaining observed STEM gender gaps.

Die Unterschiede in Dingen und Personen waren hier schon Thema, ich habe die Studie von Sue et al  hier schon besprochen. Es ist dort ein großer Effekt dieser Unterschiede festgestellt worden, der auch im Folgenden angeführt wird.

Occupation-relevant interests

Starting with occupation-relevant interests, by far the largest sex difference was that for interest in things (i.e. objects, machines or abstract rules) vs. interest in people. Members of both sexes can be found at every point on the things vs. people continuum; however, more men than women exhibit a stronger interest in things, whereas more women than men exhibit a stronger interest in people. Averaging across studies, Su et al. (2009) found an effect size of d = 0.93 for the people vs. things sex difference. This is notably larger than most human sex differences (Hyde, 2005; Lippa, 2010; Stewart-Williams & Thomas, 2013a, 2013b), and indeed than most effects in psychology (Eagly, 1995). To get an intuitive sense of the magnitude of the difference, if one were to pick pairs of people at random, one man and one woman, the man would be more things-oriented than the woman around 75% of the time.

The people vs. things sex difference immediately suggests an explanation – or rather a partial explanation – for the fact that men outnumber women in fields such as physics, engineering and mathematics, whereas women are at parity with or even outnumber men in psychology, the social sciences and the health sciences: the former fields are of interest to more men than women, and the latter to more women than men, and people tend to gravitate to fields that interest them most (Diekman et al., 2017; Yang & Barth, 2015).¹

Natürlich ist damit erst einmal noch nichts über die Gründe gesagt. Allerdings fordert auch keine Feministin, dass Frauen „Dingeorientierter“ werden sollen. 

Preferences for specific occupations

Research looking at preferences for specific occupations leads to a similar conclusion. As Su et al. (2009) report, males on average express considerably more interest than females in engineering (d = 1.11), and somewhat more interest in science and mathematics (d = 0.36 and 0.34, respectively). These differences are present by early adolescence and closely match the observed numbers of men and women working in the relevant fields. Su et al. (2009) point out that, if we make the reasonable ballpark assumption that people working in a given field tend to come from the 25% of people most interested in that field, sex differences in occupational interests would account for the entirety of the engineering gender gap and much of the gap in science and mathematics. In short, sex differences in occupational and academic preferences are far from trivial, and plausibly make a substantial contribution to observed occupational gender gaps.

Das zeigt also schon ganz erhebliche Unterschiede, die sich auch auswirken. 

Life priorities

Gender gaps in STEM – and especially in the higher echelons of STEM – may also be shaped in part by average sex differences in life priorities. As with occupational preferences, people vary a lot in their life priorities, and the full range of priorities can be found within each sex. Nonetheless, some priorities are more common among men than women, and others among women than men (Bolotnyy & Emanuel, 2019; Hakim, 2005, 2006; Konrad et al., 2000; Schwartz & Rubel, 2005). One longitudinal study found, for instance, that among adults identified as intellectually gifted in early adolescence, the average man reported placing more importance on career success and income than did the average woman, whereas the average woman reported placing more importance on work–life balance and making time for one’s family and friends (Benbow et al., 2000; Lubinski et al., 2014).

Die Studien waren bereits hier besprochen worden

These differences were particularly pronounced among people with children, apparently because women’s priorities shifted after they became mothers (Ferriman et al., 2009). Moreover, sex differences in self-reported priorities were evident in real-world behaviour. As Lubinski et al. (2014) observed, for instance, over the course of the last 15 years, the men in their sample spent an average of 51 hours a week doing paid work, whereas the women spent an average of 40.

Die einen nennen es Prioritäten, die andere „Unterdrückung und Ausbeutung der Frau durch das Patriarchat“. 

Of course, sex differences in lifestyle preferences do not explain why the sex ratio is so much more male-biased in maths-intensive STEM fields than in most others. Still, the differences do plausibly help to explain the fact that, in STEM and elsewhere, men outnumber women among the minority in the higher echelons: rising to the top is a priority for fewer women than men, and thus fewer women than men are willing to make the sacrifices required to achieve that goal. To be clear, some women are willing to make those sacrifices, and the majority of men are not. However, more men than women are willing, and this is plausibly part of the reason that the sex ratio at the top is so often male-biased. Note that, according to one large US study (N ≈ 4000), the sex difference in career-mindedness is not a result of women thinking that career advancement is impossible for them. The average woman views advancement as just as achievable as the average man, but as less desirable (Gino et al., 2015).

Die meisten Frauen denken also, dass sie durchaus Karriere machen könnten, aber finden das weit weniger interessant. 

Ich verlinke mal den Abstrakt der Studie:

Significance

We identify a profound and consistent gender gap in people’s core life goals. Across nine studies using diverse sample populations (executives in high-power positions, recent graduates of a top MBA program, undergraduate students, and online panels of working adults) and over 4,000 participants, we find that, compared to men, women have a higher number of life goals, place less importance on power-related goals, associate more negative outcomes (e.g., time constraints and tradeoffs) with high-power positions, perceive power as less desirable, and are less likely to take advantage of opportunities for professional advancement. Women view high-level positions as equally attainable as men do, but less desirable. Our findings advance the science of gender, goals, organizational behavior, and decision making.
Abstract
Women are underrepresented in most high-level positions in organizations. Though a great deal of research has provided evidence that bias and discrimination give rise to and perpetuate this gender disparity, in the current research we explore another explanation: men and women view professional advancement differently, and their views affect their decisions to climb the corporate ladder (or not). In studies 1 and 2, when asked to list their core goals in life, women listed more life goals overall than men, and a smaller proportion of their goals related to achieving power at work. In studies 3 and 4, compared to men, women viewed high-level positions as less desirable yet equally attainable. In studies 5–7, when faced with the possibility of receiving a promotion at their current place of employment or obtaining a high-power position after graduating from college, women and men anticipated similar levels of positive outcomes (e.g., prestige and money), but women anticipated more negative outcomes (e.g., conflict and tradeoffs). In these studies, women associated high-level positions with conflict, which explained the relationship between gender and the desirability of professional advancement. Finally, in studies 8 and 9, men and women alike rated power as one of the main consequences of professional advancement. Our findings reveal that men and women have different perceptions of what the experience of holding a high-level position will be like, with meaningful implications for the perpetuation of the gender disparity that exists at the top of organizational hierarchies.

Eigentlich auch wieder so etwas, bei dem man meint, dass es eigentlich recht offensichtliche Feststellungen sind. 

 

The nature and nurture of sex differences in preferences and priorities

Sex differences in occupational preferences and priorities suggest one possible reason that more men than women go into maths-intensive STEM fields. The reason, put simply, is that more men than women want to go into these fields. To the extent that this is the case, it implies that workplace discrimination accounts for a smaller fraction of the gender disparities in STEM than we might otherwise suppose. That said, even if preferences explained the entirety of observed STEM gender gaps (which we are not suggesting), this would not imply that discrimination plays no role. After all, preference differences themselves need to be explained, and some would argue that sexist stereotypes and discriminatory socialization practices are the primary drivers of these differences.

Das ist das, was ich auch schon oben angeführt habe: Die Frage wäre warum die Unterschiede bestehen. 

For many decades now, this has been the dominant explanation in the social sciences, and the one most often highlighted in papers and discussions of the topic (e.g. Cheryan et al., 2015; Dasgupta & Stout, 2014). Preferences and priorities do not just appear in a vacuum, point out proponents of this position; they are powerfully shaped by the people and the world around us. Parents, teachers and other authority figures may inadvertently nudge boys towards object-related activities, and girls towards person-related activities. Engagement in these activities may then help to kindle an interest in them among boys and girls, respectively – after all, not only do interests help shape activities but activities help shape interests (Schmidt, 2011). In addition to parental nudging, children may nudge themselves in certain directions. Most children display a stronger preference for activities they learn are preferred by members of their own sex, even in studies looking at novel and unfamiliar activities (Shutts et al., 2010; although see Hines et al., 2016). As such, if children pick up the traditional stereotype that STEM is primarily for boys, boys’ interest may spike while girls’ may often dwindle. Stereotypes about STEM careers may have similar effects. Careers in STEM are commonly perceived as male-dominated (Miller et al., 2018), and as involving social isolation and a strong focus on inanimate materials and mechanisms (Cheryan et al., 2015). This may make a career in STEM seem unappealing to more girls than it does boys. Finally, girls and women may experience bias in the STEM classroom or workplace, or come to believe this is likely, and this too may cause a decline in their interest not only in STEM careers but also in STEM subjects themselves (Thoman & Sansone, 2016).²

Finde ich eine faire Zusammenfassung der sozialen Positionen. 

But although social factors like these no doubt help to shape sex differences in interests and occupational preferences, several lines of evidence suggest that the differences are also shaped in part by unlearned biological factors.
First, sex differences in occupational preferences have remained remarkably stable throughout the half-century or so that psychologists have measured them, even in the face of significant shifts in women’s social roles and place in society (Su et al., 2009). In particular, the sex difference in interest in things vs. people seems stubbornly resistant to change. One analysis found, for instance, that whereas the number of women pursuing high-status professions increased a great deal since the 1970s, the number pursuing things-related professions remained virtually static (Lippa et al., 2014). Notably, this was the case despite the fact that, during the same period, a wide range of initiatives were established to try to entice women into those very professions. The stubbornness of the people-vs.-things sex difference is not what one would expect if the difference were shaped largely by culture.

Second, the same sex differences in occupational preferences have been found in every society where psychologists have looked for them. In one large study (N ≈ 200,000), Lippa (2010) found the differences in 53 out of 53 nations: a level of cross-cultural unanimity almost unheard of within psychology. Importantly, the gender gap in occupational preferences was no larger in nations with higher levels of gender inequality, suggesting that gender inequality is not a major determinant of the gap. Meanwhile, other research suggests that the gender gap in STEM career pursuit (as opposed to STEM-related career preferences) is actually smaller in more gender unequal nations, perhaps in part because economic hardship in those nations means that people have less scope to act on their personal preferences, and a greater need to place financial security above self-fulfilment in choosing a suitable occupation (Stoet & Geary, 2018).³

Das klassische Gender Equality Paradox und der Umstand, dass man die Unterschiede weltweit findet ist schon ein interessantes Zeichen. 

Third, at least some of the relevant sex differences appear in a nascent form early in the developmental process. Indeed, the first glimmer of the people vs. things difference may be evident in the first few days of life. Connellan et al. (2000) presented 102 newborn babies with two objects, one after the other: a human face and a mechanical mobile. Many babies looked for equal amounts of time at both. However, among those who looked for longer at one than the other, more boys than girls looked for longer at the mobile (43% vs. 17%), whereas more girls than boys looked for longer at the face (36% vs. 25%). Various criticisms have been raised against the Connellan et al. study, including the fact that it is unclear whether the stimuli the researchers used map onto the people-vs.-things orientation (see, e.g. Spelke, 2005). One reason to take the findings seriously, though – and in particular, the findings related to females’ heightened interest in social stimuli – is that analogous results have been observed in at least one nonhuman primate: among macaques, newborn females are more attentive to faces than are newborn males (Simpson et al., 2016).

Bei den Neugeborenen und den Makaken wird man kein Patriarchat annehmen können, welches die Ergebnisse beeinflusst. Insofern schon interessant, dass sich dort die Unterschiede zeigen

Finally, several lines of evidence suggest that people’s interests, career preferences and life priorities are shaped in part by prenatal hormones. The most persuasive evidence comes from research on females with congenital adrenal hyperplasia (or CAH), a condition involving exposure to abnormally high levels of prenatal androgens. CAH females tend to be more things-oriented and less people-oriented than the average female (Beltz et al., 2011). As children, they tend to be more interested in male-dominated occupations such as architect or engineer (Berenbaum, 1999), and as adults, they’re more likely to work in such occupations (Frisén et al., 2009). CAH females also tend to be less interested in infants, less interested in becoming mothers and more interested in having a career rather than staying at home (Dittmann et al., 1990; Leveroni & Berenbaum, 1998; Mathews et al., 2009).

Siehe dazu auch diesen Artikel und weitere. Die CAH-Mädchen sind in der Tat ein großes Problem für Theorien, die allein auf gesellschaftliche Einflüsse abstellen. Eine wirkliche Erwiderung die dieses Argument entkräftet habe ich noch nicht gelesen. 

Evidence from non-clinical samples points in a similar direction. One research group found that prenatal testosterone levels, measured via amniocentesis, are negatively correlated with eye contact at one year of age (Lutchmaya et al., 2002), and quality of social relationships at four (Knickmeyer et al., 2005), consistent with a prenatal contribution to the people-vs.-things sex difference. Furthermore, a large Internet survey found that women exposed to higher levels of androgens in the womb, indexed by 2D:4D ratios (that is, the ratio of the index finger to the ring finger), are more likely to work in male-dominated professions (Manning et al., 2010).⁴ Certainly, some of these findings have yet to be independently replicated, and certainly the hormonal evidence is somewhat mixed, with small sample sizes increasing the risk of both false positives due to chance and false negatives due to insufficient power (Berenbaum & Beltz, 2011). This precludes any definitive conclusions about the role of prenatal hormones. Still, the available hormonal data are at the very least suggestive, and in our view, quite persuasive. Taken together with the other data surveyed in this section, it seems reasonable to think that sex differences in interests, occupational preferences and life priorities are not purely a product of culture or socialization. Biology plays a role as well.

Und da stellt sich natürlich die Frage, wie groß der Anteil ist und welcher Anteil bei der Gesellschaft zu sehen ist

Evolutionary rationale

Although we have good reason to think that there is an inherited contribution to men and women’s occupational and lifestyle preferences, we have much less idea why this might be the case. The most plausible evolutionary explanation is for sex differences in lifestyle preferences. In most parental species, females invest more than males into offspring (Janicke et al., 2016; Trivers, 1972). Among mammals, for instance, females gestate and nurse the young, and females usually provide the bulk of the direct parental care. In our species, sex differences in parental investment are comparatively modest: both sexes tend to invest substantially in their young, rather than only the females. But there is still a difference; men in all known cultures invest less into offspring than women, and this has probably been the case for most of our evolutionary history (Stewart-Williams & Thomas, 2013b). Importantly, the minimum biological investment is also notably smaller for men than for women. Women’s minimum is a nine-month pregnancy and – until recently – several years of breastfeeding. Men’s minimum is the time and effort required to impregnate the woman.

Alleine die Betrachtung über das Minimum legt dar, dass es einen erheblichen biologischen Druck für Geschlechterunterschiede gibt. Männer können die Kinderbetreuung weit eher an Frauen abgeben, weswegen eine echte Vaterschaft im Tierreich auch sehr selten ist. Beim Menschen existiert sie, aber die väterliche Unterstützung besteht auch viel in der Ressourcenherbeischaffung während die Pflege des Säuglings schon aufgrund der Muttermilch eher bei der Frau verblieben sein dürfte. 

As a result of these sex differences in parental investment, ancestral men could potentially produce many more offspring than ancestral women, simply by mating with multiple partners (Clutton-Brock & Vincent, 1991). Consequently, human males evolved to be more interested than females in seeking multiple partners (Schmitt, 2005; Schmitt & International Sexuality Description Project, 2003), less choosy about their low-commitment sexual partners (Buss & Schmitt, 1993; Kenrick et al., 1993), and – of particular relevance to the present topic – more inclined to compete and take risks to obtain the status and resources that typically made them attractive to women (or women’s families, in the case of arranged marriages; Byrnes et al., 1999; Daly & Wilson, 2001; M. Wilson & Daly, 1985). In light of this theoretical framework – which is well-supported by research on other species (Andersson, 1994; Janicke et al., 2016) – it is little surprise that more men than women prioritize the pursuit of status over family, whereas more women than men prioritize family and work–life balance.

Auch diese Begründung finde ich nach wie vor schlüssig und durchaus stimmig. Für Männer lohnt sich klassischerweise Status und der Aufbau von Ressourcen eher, auch weil es sich dann wieder als Auswahlkriterium für Frauen für Kurzzeit- und Langzeitstrategien lohnen kann. 

Evolutionary explanations for sex differences in occupational preferences are somewhat more of a stretch. For most of human evolution, there were no scientists, no technologists, no engineers or mathematicians. As such, any innate contribution to sex differences in interest in these vocations must be a byproduct of traits selected for other reasons. One possibility is that the differences trace back to the sexual division of labour among our hunter-gatherer forebears, and specifically the fact that women specialized in caring for the young, whereas men specialized in hunting and perhaps waging war with other groups (a division of labour found as well among our close relatives, the chimpanzees; Muller et al., 2017). To fit them to these roles, women may have evolved a stronger attentiveness to the needs of the young, and to people in general (Hrdy, 2009; S. E. Taylor et al., 2000), whereas men may have evolved a stronger interest in the tools used for hunting and warfare (Archer, 2019; Geary, 2010). Sex differences in interest in people-focused vs. things-focused occupations may be an adaptively neutral side effect of these ancient, more primal differences. It is worth emphasizing that, although this hypothesis seems reasonable, it has yet to be rigorously tested. Regardless of the ultimate explanation, however, the evidence for an inherited contribution to the relevant sex differences is strong.

Auch diese Erklärung finde ich durchaus überzeugend. Für Frauen könnten Menschen einfach in vielen Punkten wichtiger gewesen sein, weil sie das Baby nie aus den Augen verlieren durften und sie aufgrund ihrer geringeren Körperkraft etc auch weit eher auf Rückhalt angewiesen waren. Rückhalt und das Bilden von Koalitionen war natürlich auch für Männer wichtig, aber wer wichtige Technik herstellen konnte oder bessere Werkzeuge hatte war gleichzeitig natürlich auch für Koalitionen interessanter. Eine Frau, die sich in gleicher Weise in einem „dinglichen Hobby“ verliert hat den Nachteil, dass das mit der Kinderbetreuung schwer zu vereinbaren ist.