Monday, October 7, 2019

China: Military-Technological Superiority and the Limits of Imitation, Reverse Engineering, and Cyber Espionage

Why China Has Not Caught Up Yet: Military-Technological Superiority and the Limits of Imitation, Reverse Engineering, and Cyber Espionage. Andrea Gilli and Mauro Gilli. International Security, Volume 43 , No. 3, Winter 2018/19, p.141-189, February 15, 2019.

Abstract: Can countries easily imitate the United States' advanced weapon systems and thus erode its military-technological superiority? Scholarship in international relations theory generally assumes that rising states benefit from the “advantage of backwardness.” That is, by free riding on the research and technology of the most advanced countries, less developed states can allegedly close the military-technological gap with their rivals relatively easily and quickly. More recent works maintain that globalization, the emergence of dual-use components, and advances in communications have facilitated this process. This literature is built on shaky theoretical foundations, however, and its claims lack empirical support. In particular, it largely ignores one of the most important changes to have occurred in the realm of weapons development since the second industrial revolution: the exponential increase in the complexity of military technology. This increase in complexity has promoted a change in the system of production that has made the imitation and replication of the performance of state-of-the-art weapon systems harder—so much so as to offset the diffusing effects of globalization and advances in communications. An examination of the British-German naval rivalry (1890–1915) and China's efforts to imitate U.S. stealth fighters supports these findings.

Three developments help account for the increase in the complexity of military technology since the second industrial revolution. First, the number of components in military platforms has risen dramatically: in the 1930s, a combat aircraft consisted of hundreds of components, a figure that surged into the tens of thousands in the 1950s and to 300,000 in the 2010s.49 As the number of components expands, the number of potential incompatibilities and vulnerabilities increases geometrically. Ensuring the proper functioning and mutual compatibility of all the components and of the whole system thus becomes increasingly difficult.50

Second, advancements in electronics, engineering, and material sciences have resulted in the components of major weapon systems becoming dramatically more sophisticated, leading military platforms to become “systems of systems.”51 Integrating large numbers of extremely advanced components, subsystems, and systems poses a daunting challenge. More sophisticated components have extremely low tolerances, which in turn require a degree of accuracy and precision in design, development, and manufacturing that was unthinkable a century ago.52 For instance, aircraft engines in the 1900s and 1910s were “crude” mechanical devices that self-taught individuals could design, assemble, and install in their own repair shops.53 In contrast, the production of today's aircraft engines is so technologically demanding that only a handful of producers around the world possess the necessary technical expertise.54 Consider that in turbofan engines, a “close clearance between [a rotary] part and its surroundings can be critical. One-tenth of 1 millimeter [i.e., 0.00393 inch] variation in dimension can have a significant impact on system compatibility.”55 The same is true of materials, electronics, and software, where minor imprecisions can have dramatic consequences.56 For example, in modern jet fighters, software controls everything, from the operation of radars to the supply of oxygen. The expansion of onboard software functions is reflected in the increase in the number of software code lines from 1,000 in the F-4 Phantom II (1958), to 1.7 million in the F-22 (2006), and to 5.6 million in the F-35 Joint Strike Fighter/Lightning II (2015).57 Even a minor problem in those millions of lines of code could ground the aircraft or prove fatal.58 This level of sophistication explains why software engineering is responsible for most of the delays and of the problems seen in advanced weapon systems.59 Third, modern weapon systems can now perform in extraordinarily demanding environmental and operational conditions, thanks to improvements in all metrics (e.g., speed, altitude ceiling for aircraft, and collapse depth for submarines).60 These improvements, however, have increased the likelihood of technical problems.61 The more sophisticated a component is, the more likely minor environmental changes will affect its performance.62 In addition, as technological advances permit weapon systems to operate in once unfamiliar environmental conditions, designers and engineers are forced to deal with previously unknown physical phenomena.63


After World War II, the advent of rocket engines, radio communications, automatic guidance and control, and high-speed aerodynamics created new challenges. In response, aircraft manufacturers had to broaden and deepen their knowledge base to include fields such as weapons design, avionics, and material structures, as well as the training of aircrews, combat tactics, and, most importantly, human physiology and atmospheric sciences.96 With supersonic speed and subsequent advances, the number and sophistication of disciplines required for aircraft development expanded to the point of being well ahead of scientific knowledge and understanding.97 Work on the SR-71 Blackbird exemplifies these trends. Because of the friction resulting from flying at three times the speed of sound, the body of the Blackbird was exposed to temperatures above 600°F. To address the resulting problems, Lockheed had to develop “special fuels, structural materials, manufacturing tools and techniques, hydraulic fluid, fuel-tank sealants, paints, plastic, wiring and connecting plugs, as well as basic aircraft and engine design.”98 With the transition to fly-by-wire, the absorptive capacity requirements grew by an order of magnitude, as aircraft production expanded to a broad set of highly demanding fields such as electronics, computer science, and communications, with “software construction [being] the most difficult problem in engineering.”99 Moreover, given the nature of these disciplines, the margin for error has continued to shrink: a minor glitch in the software or the exposure of the hardware to unforgiving conditions (e.g., extreme heat, cold, or humidity) can be fatal.100


In the second half of the nineteenth and early twentieth centuries, manufacturing benefited from unprecedented and possibly unique synergies and economies of scope.102 The relatively low level of technological complexity imposed fairly loose requirements, permitting the adoption across different industries of the same machine tools, the same industrial processes, and the same know-how.103 For instance, problems related to automobile production were “not fundamentally different from those which had already been developed for products such as bicycles and sewing machines.”104 As a result, “the skills acquired in producing sewing machines and bicycles greatly facilitated the production of the automobile.”105 With mass production, the opportunities for synergies and economies of scope among different industries expanded even further.106 Automobile manufacturers during World War I could easily enter the business of aircraft and tank production by exploiting their existing industrial facilities and know-how.107 Within a year of starting to produce aircraft engines, Rolls-Royce was delivering a very reliable and high-performing engine (the “Eagle”). Similarly, during the war, the company adapted its “Silver Ghost” chassis, the same used by King George, into an armored car that proved effective during the British campaign in the Middle Eastern desert.108 Even during World War II, when the level of complexity of military technology was substantially higher than during World War I, the United States and the Soviet Union were able to convert their civilian manufacturing activities to military production at a pace and to a degree that would be unimaginable today109 As Richard Overy summarizes, “Manufacturing technically complex weapons … [such as] heavy bombers … with the methods used for Cadillacs … ultimately proved amenable.”110

Female perpetrators and the Postrefusal Sexual Persistence Scale: nonverbal sexual arousal, emotional manipulation and deception, exploitation of the intoxicated, and use of physical force or threats

Sexual Coercion by Women: The Influence of Pornography and Narcissistic and Histrionic Personality Disorder Traits. Abigail Hughes, Gayle Brewer, Roxanne Khan. Archives of Sexual Behavior, October 7 2019.

Abstract: Largely overlooked in the literature, this study investigated factors influencing women’s use of sexual coercion. Specifically, pornography use and personality disorder traits linked with poor impulse control, emotional regulation, and superior sense of sexual desirability were considered. Women (N = 142) aged 16–53 years (M = 24.23, SD = 7.06) were recruited from community and student populations. Participants completed the Narcissistic and Histrionic subscales of the Personality Diagnostic Questionnaire-4, in addition to the Cyber-Pornography Use Inventory to explore the influence of their pornography use (interest, efforts to engage with pornography, and compulsivity) on their use of sexual coercion. This was measured using four subscales of the Postrefusal Sexual Persistence Scale: nonverbal sexual arousal, emotional manipulation and deception, exploitation of the intoxicated, and use of physical force or threats. Multiple regression analyses revealed that pornography use, narcissistic traits, and histrionic traits significantly predicted the use of nonverbal sexual arousal, emotional manipulation and deception, and exploitation of the intoxicated. Effort to engage with pornography was a significant individual predictor of nonverbal sexual arousal and emotional manipulation and deception, while histrionic traits were a significant individual predictor of exploitation of the intoxicated. Findings were discussed in relation to existing sexual coercion literature and potential future research.

Keywords: Female perpetration Histrionic personality traits Narcissistic personality traits Sexually explicit material


Sexual aggression research has historically focused on male perpetration and female victimization. This approach most likely reflects the global pervasiveness of men’s sexual violence and perceptions of women as sexually passive (Denov, 2017; Krahé & Berger, 2013). However, females also sexually aggress against unwilling partners (Erulkar, 2004; Hines, 2007) and researchers have increasingly acknowledged nuances in how this might be expressed (e.g., by harassment, abuse, and coercion) (Grayston & De Luca, 1999; Ménard, Hall, Phung, Ghebrial, & Martin, 2003). Despite this, and the negative physical and psychological consequences experienced by male victims (Visser, Smith, Rissel, Richters, & Grulich, 2003), a dominant gendered perspective has resulted in a relative paucity of information on factors that may explain female sexual aggression (Campbell & Kohut, 2017; Denov, 2017). This area is worthy of investigation as pathways to sexual aggression differ for men and women (Krahé & Berger, 2017), and factors associated with sexual coercion by men may not be generalizable to female perpetrators. Indeed, Schatzel-Murphy, Harris, Knight, and Milburn (2009) found that while men and women’s sexually coercive behavior may be similar, factors symptomatic of its use might be different, with sexual compulsivity (i.e., difficulty controlling sexual urges) shown to be a dynamic influence for females. Our study, therefore, aimed to investigate factors associated with sexual compulsivity in women that might explain their use of sexually coercive behavior. Specifically, the influence of three elements of pornography use (interest, efforts to engage with pornography, and compulsivity) and narcissistic and histrionic personality traits was explored due to associations in the literature with coercive sexual tactics to obtain intimate relations.

Sexual coercion lies on the sexual aggression continuum and is defined as “the act of using pressure, alcohol or drugs, or force to have sexual contact with someone against his or her will” (Struckman-Johnson, Struckman-Johnson, & Anderson, 2003, p.76). Sexual coercion may include a range of behaviors that can be separated into four categories of increasing exploitation: (1) sexual arousal (e.g., persistent kissing and touching), (2) emotional manipulation (e.g., blackmail, questioning, or using authority), (3) alcohol and drug intoxication (e.g., purposefully getting a person drunk or taking advantage while intoxicated), and (4) physical force or threats (e.g., using physical harm). As a large body of research has established that men are more likely than women to perpetrate sexual coercion (see Krahé et al., 2015), this has overshadowed evidence that a proportion of women also report using a range of sexually coercive behavior (e.g., Hoffmann & Verona, 2018; Krahé, Waizenhöfer, & Möller, 2003; Ménard et al., 2003; Muñoz, Khan, & Cordwell, 2011; Russell & Oswald, 2001, 2002; Struckman-Johnson et al., 2003). While single studies have found female perpetration rates as high as 26% (compared to 43% for males) (see Struckman-Johnson et al., 2003), in an overview of the literature, Hines (2007) estimated rates between 10 and 20% for verbal sexual coercion, and 1 and 3% for physically forced sexual intercourse.

Due to higher rates of male perpetration, it is perhaps not surprising that fewer studies have focused on correlates of women’s sexually coercive behavior. Studies have reported that influential factors for women include peer pressure to have sex (e.g., Krahé et al., 2003), sexual compulsivity (Schatzel-Murphy et al., 2009), antagonistic attitudes toward sexual relationships (e.g., Anderson, 1996; Christopher, Madura, & Weaver, 1998; Yost & Zurbriggen, 2006), and sexual victimization experiences (e.g., Anderson, 1996; Krahé et al., 2003; Russell & Oswald, 2001). Further studies have documented the influence of a hostile personality with a dominant interpersonal style (Ménard et al., 2003) a manipulative, game-playing approach to forming intimate relations (Russell & Oswald, 2001, 2002), and pornography use (e.g., Kernsmith & Kernsmith, 2009a) thereby providing the rationale for this study.

Women’s Use of Pornography

Pornography refers to sexually explicit material developed and consumed to stimulate sexual arousal, available in versatile forms (e.g., photographs and videos) and often accessed online (Campbell & Kohut, 2017). Research has historically focused on the manner in which exposure to pornographic material influences men’s sexual attitudes and conduct. For example, it is argued that men’s use of pornography is related to sexual objectification of partners (Tylka, & Kroon Van Diest, 2015) and sexually coercive behavior (Stanley et al., 2018). Compulsive consumption of pornographic material, in particular, may be closely related to men’s sexually aggressive behavior (Gonsalves, Hodges, & Scalora, 2015). Research indicates that women also engage with pornography, although to a lesser extent than men (Ashton, McDonald, & Kirkman, 2018; Rissel, Richters, de Visser, McKee, Yeung, & Caruana, 2017). Due to disparities in methodology, estimates of women’s pornography use vary significantly across studies, ranging from 1 to 88% depending on the sample and operational definition of pornography (Campbell & Kohut, 2017). In a review of their annual statistics, Pornhub, a large Internet pornography website, reported that just over a quarter of their visitors were women and that their top trending1 search throughout 2017 was “porn for women,” representing a 1400% increase (Pornhub Insights, 2018). While some studies report that females were more likely to use pornography with a partner (e.g., Ševčíková & Daneback, 2014), other studies have found that their pornography use was more likely and more frequent when alone than with a partner (Fisher, Kohut, & Campbell, 2017).

Consistent with studies of men’s pornography consumption, research has found women’s use of pornography to be associated with attitudes toward sex, sexual conduct, and sexual activities (e.g., number of sexual partners) (Wright, Bae, & Funk, 2013). This is supported further by a recent meta-analysis that found, similar to men, women’s pornography use was associated with sexual aggression, both verbally (i.e., “verbally coercive but not physically threatening communication to obtain sex, and sexual harassment”) and physically (i.e., “use or threat of physical force to obtain sex”) (Wright, Tokunaga, & Kraus, 2016, p.191). The small number of studies in this area has meant the extent to which women’s use of pornography influences their sexually aggressive behavior remains unclear. In one such study, it was found that pornography use predicted all forms of sexual aggression in women (i.e., extortion, deceit, obligation, and emotional manipulation) except for physical violence and intimidation (Kernsmith & Kernsmith, 2009a). The dearth of literature available indicates there is scope to investigate this further, thus we consider three elements of women’s pornography use, that is (1) interest in pornography, (2) efforts to engage with pornography, in additional to (3) pornography compulsivity, which is largely overlooked despite its association with men’s sexual aggression (e.g., Gonsalves et al., 2015).

Narcissistic and Histrionic Personality Disorder Traits

Personality traits may also influence the likelihood of sexually aggressive behavior in women (Krahé et al., 2003; Russell, Doan, & King, 2017). Characteristics of the dramatic, emotional, and erratic Cluster B personality disorders (associated with poor impulse control, emotional regulation, and anger) may be particularly influential on sexual aggression (Mouilso & Calhoun, 2016). For example, narcissistic personality disorder (NPD), found in both men (7.7%) and women (4.8%) and overall in 6.2% of the general population (Stinson et al., 2008), is characterized by a grandiose sense of the self, entitlement, and low empathy for others (Emmons, 1984). In men, narcissistic personality traits are positively associated with rape supportive beliefs and negatively associated with empathy for rape victims (Bushman, Bonacci, van Dijk, & Baumeister, 2003), while NPD is related to perpetration of sexual aggression (Mouilso & Calhoun, 2016). Women with higher levels of narcissism display more negative relationship communication (Lamkin, Lavner, & Shaffer, 2017) and are more likely to engage in sexual harassment (Zeigler-Hill, Besser, Morag, & Campbell, 2016). Pertinently, narcissism is associated with women’s perpetration of sexual coercion (Kjellgren, Priebe, Svedin, Mossige, & Långström, 2011; Logan, 2008), with the entitlement/exploitativeness dimension found to be most influential (Blinkhorn, Lyons, & Almond, 2015; Ryan, Weikel, & Sprechini, 2008). Additionally, females high in narcissism were found to be just as likely as their male counterparts to react with persistence and sexually coercive tactics after being denied during a sexual advance (Blinkhorn et al., 2015). In part, this behavior may reflect the tendency for narcissistic individuals to engage in sex in order to fulfill their need for self-affirmation (Gewirtz-Meydan, 2017).

Found in 1–3% of general population (Torgersen et al., 2000) and reported twice more in women than in men (Torgersen, Kringlen, & Cramer, 2001), traits associated with histrionic personality disorder (HPD) are far less explored than NPD in relation to sexual coercion. This is somewhat surprising as defining characteristics of HPD include excessively emotional, impulsive, attention seeking behavior, and inappropriate or competitive sexual conduct (APA, 2013; Dorfman, 2010; Stone, 2005). Emotionally manipulative and intolerant of delayed gratification (Bornstein & Malka, 2009; Stone, 2005), women with HPD demand confirmation and attention from intimate partners (AlaviHejazi, Fatehizade, Bahrami, & Etemadi, 2016). A study that compared women with HPD to a matched control group without personality disorders found they were more likely to have been sexually unfaithful and report greater sexual preoccupation and sexual boredom with lower levels of sexual assertiveness and relationship satisfaction (Apt & Hurlbert, 1994). Furthermore, Apt and Hurlbert considered that HPD behavioral traits were indicative of sexual narcissism, while Widiger and Trull (2007) noted that HPD and NPD traits were likely to co-occur. The dominant, manipulative, and sexually compulsive behavioral traits found in these studies of women with NPD and HPD are pertinent as they align with extant studies reporting factors underpinning women’s perpetration of sexual coercion (e.g., Russell & Oswald, 2001, 2002; Schatzel-Murphy et al., 2009) and pornography use (e.g., Wright et al., 2013, 2016). Hence, additional research is necessary to examine the influence of both HPD and NPD traits and pornography use on women’s use of sexual aggression.

Check also Tactics of sexual coercion: when men and women won't take no for an answer. Struckman-Johnson C1, Struckman-Johnson D, Anderson PB. J Sex Res. 2003 Feb;40(1):76-86.

Abstract: We investigated women's and men's reports of experiencing and using tactics of postrefusal sexual persistence, defined as persistent attempts to have sexual contact with someone who has already refused. Participants were 275 men and 381 women at Midwestern and Southern universities. More women (78%) than men (58%) reported having been subjected to such tactics since age 16; this difference was significant for the categories of sexual arousal, emotional manipulation and lies, and intoxication, and for two tactics within the physical force category (physical restraint and threats of harm). More men (40%) than women (26%) reported having used such tactics; this difference was significant for the sexual arousal, emotional manipulation and lies, and intoxication categories. We present participants' written descriptions of their experiences.

Study on the economics of ethnic enclaves (communities with high concentrations of one ethnic group usually resulting from immigration patterns)

The Economics of Ethnic Enclaves. Alex Nowrasteh. Cato at Liberty, October 3, 2019.

Full text and links at the e-addres above.


Ethnic enclaves are communities with high concentrations of one ethnic group usually resulting from immigration patterns. Many scholars believe that ethnic enclaves slow immigrant assimilation into American society, a phenomenon known as the “enclave thesis.” Recent academic literature on the enclave thesis has yielded mixed results, but there are also severe research design problems due to data limitations, a lack of definitional consensus, and seemingly insurmountable endogeneity. This post will analyze key findings within the ethnic enclave literature.

Background and Definitions


Major Findings

Many studies exploit the exogenous placement of refugees by governments as quasi-natural experiments to study how the assimilation rates of those placed in ethnic enclaves compare to those who do not settle in ethnic enclaves. Since government agencies make the settlement decisions for refugees, endogeneity is less of a concern. A recent study by the National Academy of Sciences by Linna Martén, Jens Hainmueller, and Dominik Hangartner (2019) analyzed the marginal effect of increased ethnic clustering on employment outcomes by using Switzerland’s dispersal placement program for recently arrived refugees. The program assigns refugees to specific regions in the country. This program allowed researchers to compare labor market outcomes between the government-placed refugees and non-refugee immigrants who chose to settle in ethnic enclaves. The study found that settling in an ethnic enclave increased the probability of employment in Switzerland. These effects were observed with respect to the number of co-nationals, ethnicity, and language concentration in said enclaves, indicating robust short- and medium-term results.

Sweden used a similar placement strategy for refugees. Economists Per-Anders Edin, Peter Fredriksson, and Olof Åslund (2003) discovered that a one standard deviation increase in an area’s co-ethnic population caused a 13 percent bump in earnings for low-skilled immigrants of the same ethnicity placed in the area by the government. Another study of an exogenous refugee-placement program in Denmark reached three conclusions: first, there is “strong evidence that refugees with unfavorable unobserved characteristics self‐select into ethnic enclaves. Second, a relative standard deviation increase in the ethnic enclave size increases annual earnings by 18 percent on average, irrespective of skill level. Third, further findings are consistent with the explanation that ethnic networks disseminate job information, which increases the job‐worker match quality and thereby the hourly wage rate.”

Some studies, however, suggest opposite employment effects, particularly for low-skilled immigrants in ethnic enclaves. For example, George Borjas (2000) measured the impact residential segregation has on “economic assimilation,” or the convergence of immigrant wages with their native-born counterparts. Borjas found that increased residential segregation led to adverse wage effects for both newly arrived and least-educated immigrants. He also observed that increased residential sorting into ethnic enclaves lowers the likelihood an immigrant will become English-proficient but increases the likelihood they will further their education. Borjas attributes these negative results to the lack of diversity within ethnic neighborhoods after 1965, suggesting that the increased homogeneity among immigrants is depressing labor market opportunities and assimilation practices.

The National Institutes of Health found that higher ethnic concentrations in enclaves yield negative employment effects for immigrants in the United States. Hispanic immigrants living in an enclave face an almost 11 percent reduction in earnings relative to Hispanics who live elsewhere, a figure which translates to an approximate $1.37 hourly wage reduction. The authors caution, however, that their small sample size may prevent their results from representing all ethnic groups.

Another study by economists Roberto Pedace and Stephanie Rohn Kumar (2012) evaluated the effects of increased ethnic concentrations on wages and employment propensities for several ethnic groups in the United States, including Mexicans, Central Americans, Cubans, Chinese, and Indians. For Mexican, Puerto Rican, and Cuban males, the overall wage effects of living in an ethnic enclave were negative and statistically significant. For higher educated Korean and Indian immigrants, however, the opposite was true. In addition, economists Barry Chiswick and Paul Miller (2005) found that the costs of increased competition (supply) inside an ethnic enclave offset the potential economic gains from larger ethnic networks in California.

Entrepreneurship inside ethnic enclaves also affects whether their members receive net positive or negative economic impacts. Per-Anders Edin, Peter Fredriksson, Olof Åslund (2003) conclude that higher rates of ethnic self-employment put upward pressure on wages. Alejandro Portes (1987) describes the importance of Cuban-owned banking services that extended funds to recent immigrants with little collateral. These services immensely contributed to the entrepreneurial vibrancy of Miami, especially in the wake of the Mariel Boatlift. Additionally, economist Maude Toussaint-Comeau found that as the size of the ethnic network increases (an indicator of the enclave’s quality), so does the probability that immigrants are self-employed.

A major qualification in the above-cited literature is that increasing an enclave’s educational quality significantly improves employment outcomes and rates of cultural assimilation, such as English language acquisition. For instance, Anna Daam (2014) found that in Denmark, co-ethnics with higher skills and employment rates matter far more than the nominal size of the ethnic enclave. In other words, improving the human capital within and around the ethnic enclave has a far greater effect on immigrant economic success than whether or not immigrants live in ethnic enclaves. The Institute of Labor Economics surveyed the literature and observed that improved quality measures, like education and income, are more important than the scale of an enclave. Economists David M. Cutler, Edward L. Glaeser, Jacob L. Vigdor (2007) also found that an immigrant’s education is more important than his residence in an ethnic enclave. Another study indicates that increased legalization status for immigrants increases immigrant wages and the likelihood they will become naturalized citizens.



Michael N. Peterson helped research and write this blog post.

Large increases in gasoline prices between the ages of 15-18 significantly reduce the likelihood of driving a private automobile to work & the total annual vehicle miles traveled later in life; also increases public transit use

Formative Experiences and the Price of Gasoline. Christopher Severen & Arthur A. van Benthem. Federal Reserve Bank of Philadelphia Working Paper WP 19-35, September 2019.

Abstract: An individual’s initial experiences with a common good, such as gasoline, can shape their behavior for decades. We first show that the 1979 oil crisis had a persistent negative effect on the likelihood that individuals that came of driving age during this time drove to work in the year 2000 (i.e., in their mid 30s).  The effect is stronger for those with lower incomes and those in cities.  Combining data on many cohorts, we then show that large increases in gasoline prices between the ages of 15 and 18 significantly reduce both (i) the likelihood of driving a private automobile to work and (ii) total annual vehicle miles traveled later in life, while also increasing public transit use.  Differences in driver license age requirements generate additional variation in the formative window.  These effects cannot be explained by contemporaneous income and do not appear to be only due to increased costs from delayed driving skill acquisition.  Instead, they seem to reflect the formation of preferences for driving or persistent changes in the perceived costs of driving.

Keywords:  formative experiences, preference persistence, path dependence, drivingbehavior, gasoline price
JEL Codes: D12, D90, L91, Q41, R41

Individual variations in the modular organization of functional brain networks: higher intelligence seems associated with higher temporal stability (lower temporal variability) of brain network modularity

Temporal stability of functional brain modules associated with human intelligence. Kirsten Hilger et al. Human Brain Mapping, October 6 2019.

Abstract: Individual differences in general cognitive ability (i.e., intelligence) have been linked to individual variations in the modular organization of functional brain networks. However, these analyses have been limited to static (time‐averaged) connectivity, and have not yet addressed whether dynamic changes in the configuration of brain networks relate to general intelligence. Here, we used multiband functional MRI resting‐state data (N = 281) and estimated subject‐specific time‐varying functional connectivity networks. Modularity optimization was applied to determine individual time‐variant module partitions and to assess fluctuations in modularity across time. We show that higher intelligence, indexed by an established composite measure, the Wechsler Abbreviated Scale of Intelligence (WASI), is associated with higher temporal stability (lower temporal variability) of brain network modularity. Post‐hoc analyses reveal that subjects with higher intelligence scores engage in fewer periods of extremely high modularity — which are characterized by greater disconnection of task‐positive from task‐negative networks. Further, we show that brain regions of the dorsal attention network contribute most to the observed effect. In sum, our study suggests that investigating the temporal dynamics of functional brain network topology contributes to our understanding of the neural bases of general cognitive abilities.


Intelligence describes our ability to reason, to understand complex ideas, to learn from experiences, and to adapt effectively to the environment (Neisser et al., 1996). Understanding the biological bases of human intelligence is an important scientific aim, and neuroscientific research has begun to contribute insights about how individual differences in brain function (Duncan, 2005; Sripada, Angstadt, & Rutherford, 2018), brain structure (Gregory et al., 2016; Haier, Jung, Yeo, Head, & Alkire, 2004), and intrinsic brain connectivity (Hilger, Ekman, Fiebach, & Basten, 2017a; Van den Heuvel, Stam, Kahn, & Hulshoff Pol, 2009) relate to general intelligence (for review see Basten, Hilger, & Fiebach, 2015; Jung & Haier, 2007).

Recent years have seen an increasing interest in understanding how human cognition emerges from the intrinsic organization of functional brain networks (Park & Friston, 2013), often studied using functional MRI (fMRI) in the absence of task demands (i.e., under resting‐state conditions; Biswal, Yetkin, Haughton, & Hyde, 1995). The topology of these networks determines how information is transferred between brain regions, and graph theory provides a set of tools to study these topological characteristics (Rubinov & Sporns, 2010). In the field of intelligence research, early graph‐theoretical work proposed that global properties of brain networks such as higher global network efficiency are associated with higher intelligence (van den Heuvel et al., 2009), a finding not replicated in more recent studies (Kruschwitz, Waller, Daedelow, Walter, & Veer, 2018; Pamplona, Santos Neto, Rosset, Rogers, & Salmon, 2015). In contrast, other studies have suggested that intelligence is related to efficiency in the interconnections of specific brain regions (Hilger et al., 2017a). Graph‐theoretical investigations revealed further that the human brain exhibits a hierarchically modular organization with clusters of nodes (modules, subnetworks) that are densely connected among each other but only sparsely coupled to nodes in other modules (Meunier, Lambiotte, & Bullmore, 2010; Sporns & Betzel, 2016). A modular organization balances segregated and integrated information processing, both of which are important for human cognition (Cohen & D'Esposito, 2016). Region‐specific modularity was recently also shown to covary significantly with individual differences in general intelligence (Hilger, Ekman, Fiebach, & Basten, 2017b).

The functional brain network correlates of intelligence were so far mostly studied as a static (i.e., time‐invariant) property of the human brain, that is, by averaging time courses of neural activation across the entire duration of a resting‐state fMRI scan (typically 5–10 min). This approach, however, ignores that intrinsic brain networks vary substantially across time (Cohen, 2018; Lurie et al., 2018; Zalesky, Fornito, Cocchi, Gollo, & Breakspear, 2014). Importantly, it has been shown that the dynamic interplay between states of high integration (low modularity) versus high segregation (high modularity) is linked to different levels of attention (Shine, Koyejo, & Poldrack, 2016) and cognitive performance (Shine et al., 2016). These first results suggest that the study of network dynamics has great potential for providing insights into human cognition from a mechanistic point of view — and thus also for advancing our understanding about the neural mechanisms underlying different levels of general cognitive ability.

Here, we apply graph‐theoretical modularity analyses to resting‐state BOLD fMRI data from a large sample of healthy adult humans (N = 281) to test the hypothesis that intelligence covaries significantly with the amount of dynamic reconfiguration within modularly organized, intrinsic brain networks. Going beyond previous work, we measured global modularity at different spatial scales, to gain insights into the brain's intrinsic network architecture beyond an arbitrarily chosen resolution level. The results of this analysis replicate and extend our previous finding that intelligence is not related to global modularity of static (i.e., time‐invariant) networks (Hilger et al., 2017b). Most importantly, we observed an association between intelligence and dynamic network reconfiguration, such that more intelligent persons show greater stability of network segregation over time.

Data Availability Statement: All data used in the current study can be accessed online under: The preprocessing pipeline CCS is also freely available to the public via GitHub ( or All further analysis code used in the current study has been deposited on GitHub (‐Brain‐Network‐Modularity) and Zenodo (

When evolution, human sexuality, and the Western world collide: We are failing to recognize that exciting, primal sex in a trusting, respectful relationship requires the same elements we vilify in men today

The End of Sex: When evolution, human sexuality, and the Western world collide. Marianne Brandon and James Simon. Psychology Today, Oct 06, 2019.

Note: This article is a guest post co-authored by Drs. Marianne Brandon* and James Simon*, with an epilogue by the blog author, Glenn Geher.

His wife having gone to bed early, he locked the basement door to ensure privacy. He had planned this moment all day. Unlike his wife, who seemingly had lost interest in sex years ago, his lover was waiting downstairs, eager to please.

Never critical or demanding, with such soft eyes and skin, sex had become such a pleasure. He had even come to love the way his lover pronounced his name. In spite of being a robot, she somehow managed to say it with such tenderness…..

We have become a massive, unintended sexual experiment. Our understanding of sex and gender is evolving at astonishing rates. Paradoxically, as powerful, exhilarating, and necessary as this process is for our collective future, we are simultaneously at a perilous moment for the future of intimacy and intimate relationships.

Forcing sex into a politically correct paradigm annihilates it.

Sexual frequency today is less than all prior decades studied—at least, people are having less sex with their partners. Rates of sexual dissatisfaction and sexual dysfunction are astoundingly high. This is due to a variety of factors that are merging to create a perfect storm—technological advances, mobile lifestyles, increasing daily tasks, rising expectations for long-term relationships, and information overload.

Yet there is something even more fundamentally awry. The very empowering of women and the culturally valued softening of men has suddenly created a new way of engaging in the bedroom as much as in the boardroom, and our evolutionary psychology has not caught up. This is a serious social problem because intimacy is not an expendable aspect of humanity.

Our insistence that men and women are more alike than different is true in almost all aspects of living, except for sex. Human sexuality—the sexuality of all mammals in general and primates in particular—has primal, biological roots. And when people work with, rather than against, these instincts, their sex gets better. Gender equality does not imply gender equivalence—at least, not in the bedroom.

The extraordinary gains provided by the feminist movement have been a thrilling first in modern history. Women’s expectations about sex have appropriately changed: They demand more pleasure from sex and an equal romantic partnership; women are more comfortable engaging in sexually open behaviors, including hook-ups and sexual experimentation.

It is not just women who have benefitted. In contrast to old-fashioned, male sexual stereotypes, many mature men today enjoy sexually assertive women. They appreciate a social climate that supports releasing restrictive pressures always to be ready and interested in sex: always having to be the sexual initiator, and being responsible for their partners’ sexual pleasure. These shifts are reflected in many men gravitating to sexual relationships with older women, their interest in being the primary caretaker of their children, and a decreased concern with being the primary breadwinner of a household.  

Many men are pleased to have escaped the pressure of old-fashioned stereotypes of masculinity—being eternally dominant, carrying the financial burden of the household, having a reduced role in parenting, and avoiding emotional expression. And those who identify with a non-binary sexual identity may now live authentically, with freedom of self-expression.

In spite of these many hard-fought liberties for all genders, in some surprising and very significant ways, sex has become more complicated. In the privacy of our respective psychological medical practices, we regularly hear women say, “In the bedroom, he is passive. Almost meek. It’s hard to respect him, let alone have sex with him!” Or, “He’s so cautious and hesitant in the bedroom! It’s such a turnoff.”

Outside of sexual role play in certain fetishistic circles, for most women, there is no pleasure in sexually dominating a weaker partner. For women in long-term, committed relationships, the exquisite feeling of sexual surrender may paradoxically be more likely to unfold with men who express their sensuality in a more bold, self-assured style—literally, when she’s not the strongest force in the bedroom.

The truth is, modern women enjoy the more lusty, primal aspects of love-making. Polite sex holds little interest for them—they’d rather do the dishes. And what about men? Despite the valuable outing of abhorrent men via #MeToo, our culture is filled with men who respect women, and who long to share fulfilling sexual relationships with the women they love.

These men have learned that to show respect to their female partners, they should obtain verbal permission for sex, and to avoid at all costs any behavior in the bedroom that may be regarded as aggressive or dominant. This sounds right in theory. Yet behind the closed doors of our offices, wives and girlfriends experience these men as passive and uninteresting in the bedroom. And before long, sex ceases.

What we are failing to recognize is that exciting, primal sex in a trusting, respectful relationship requires the same elements we vilify in men today. We teach men to contain their sexual interest, resist assertive overtures, and hide their sexual longing. How confusing it must be for a man to develop a sensitive, responsive, polite sexual style, only to be ultimately told by the woman he marries that he is a boring and uninteresting lover. How depressing for a woman who is confident and secure in her sexuality to feel sexually unmet by the man who is to be her sexual playmate for a lifetime!

Experiencing her partner’s sexual confidence and longing is a fundamental aspect of good sex for a majority of women. Stripping men of their sexual assertiveness diffuses women's sexual pleasure. Women are not experiencing this shift in their relationship and sexual dynamics as empowering. They are grief-stricken over what their lives are missing.

In our noble efforts to make sex politically correct, we are ignoring a fundamental aspect of sexuality. Exciting sex—primal sex—emanates from the more ancient biology we share with other mammals. Our biological nature has instilled in all male and female mammals some basic, unique instincts that make them want sex. Human bodies continue to respond to sexual triggers as our ancestors did, thousands of years ago.

Our combination of an evolved cerebral cortex coupled with our primitive sexual biology presents interesting and often challenging scenarios for us all. While our minds have matured and evolved to think in very different ways than our primate ancestors, our bodies continue to receive sexual marching orders from our more primitive brain regions. Herein lies the potential for infinite difficulty. Without comfort with our most basic sexual instincts as male or female, it is challenging to build a creative sexual repertoire with a beloved long-term partner.
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Without sex, couples describe themselves as best friends. Proud as such couples may be of feeling close and connected, they lack the desire to make love. What’s at stake here is something very basic to our humanity—our deepest connection to our chosen other, and to our own sexual selves.

We are heading down a dangerous path, yet we also have before us an extraordinary opportunity. For the first time in history, because of the equality and respect prompted by the feminist movement, we have the capacity to manifest extraordinary sex in long-term, committed relationships. Triumphantly, a woman can now choose to feel vulnerable during sex, because it feels good—not because she is forced into that role.

Exploring sex and relationships from an evolutionary perspective does not imply that men and women are destined to return to fixed sexual roles. An immutable sexual style would be unappealing for most modern couples. But comfort in our most basic instincts enables couples to manifest potent sexual reflexes that have more recently been denied.

Our next undertaking as feminists, male and female, is to return to our core and collect what is precious that we have lost in these last decades of battle. Our efforts to make sex less about the primal brain and, instead, more politically correct, are forcing exciting sex onto a darker playground. Increasingly, men and women are seeking outlets for their primal sexual energy that can be damaging to their intimate relationships, such as overuse of porn and extramarital affairs.

Sex robots will soon offer non-critical, always-available alternatives for those who find sexual relationships uncomfortably complex, anxiety-provoking, or just too much hassle. Technology can accomplish what sex used to—procreation and sexual satisfaction.

This future is not simply a sci-fi story. It is the next logical step from where we are. However, we can choose a different path. Passionate love-making and intimacy do not have to be a casualty of our social growth. Harnessing sexual instincts within a trusting, mutually respectful, intimate relationship can offer the glue that keeps intimacy strong and desirable. It feeds more than our sexual needs; it feeds the soul of our humanity.

Epilogue (by Glenn Geher)

Understanding our sexuality is foundational to understanding the human experience. The nature of human sexuality evolved over millennia. Reproduction is as basic as any process when it comes to the living world.

Cultural evolution, which is ultimately a product of our biological evolution, progresses at a rapid pace compared with the pace of organic evolution. Cultural evolution is exciting and profound. As Drs. Brandon and Simon have articulated so clearly here, norms surrounding relationships and sexuality, resulting from cultural evolution, have been advancing at breakneck speed over the past several decades, leading to all kinds of novel attitudes, beliefs, and technologies.

While our brave new world has lots of amazing new opportunities and affordances for all of us, we need to always keep in mind that the modern world is deeply mismatched from ancestral human conditions in many important ways (see our new book, Positive Evolutionary Psychology, Geher & Wedberg, 2020). And evolutionary mismatch often leads to problems.

When modern technology and human mating meet head-on, as is the case with sex robots and pornography, we need to look before we leap. Our evolved relationship psychology is the result of thousands of generations of organic evolution. As Drs. Brandon and Simon warn, we ignore our evolved sexual psychology to our own peril.

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*Dr. Brandon is a clinical psychologist and Diplomat in sex therapy. She is the author of Monogamy: The Untold Story, co-author of Reclaiming Desire: 4 Keys to Finding Your Lost Libido, and author of the ebook Unlocking the Sexy In Surrender: Using the Neuroscience of Power to Recharge Your Sex Life, as well as professional articles exploring evolutionary theory and sexuality, the challenges of monogamy, gender differences in sexual expression, and aging and sex.

*Dr. Simon is a clinical professor of obstetrics and gynecology at the George Washington University School of Medicine, and he is the current President of the International Society for Study of Women’s Sexual Health. Dr. Simon served as principal investigator on more than 300 clinical trials, research grants, and scholarships in the area of women's health. He has consistently been ranked as a top doctor nationally and internationally.


Geher, G. & Wedberg, N. (2020). Positive Evolutionary Psychology: Darwin’s Guide to Living a Richer Life. New York: Oxford University Press.

Glenn Geher, Ph.D., is professor of psychology at the State University of New York at New Paltz. He is founding director of the campus’ Evolutionary Studies (EvoS) program.