Samstag, 30. Mai 2015

Beyond a bigger brain: Multivariable structural brain imaging and intelligence

Beyond a bigger brain: Multivariable structural brain imaging and intelligence 
Stuart J. Ritchie, Tom Booth, Maria del C. Valdés Hernández, Janie Corley, Susana Muñoz Maniega, Alan J. Gow, f, Natalie A. Royle, Alison Pattie, Sherif Karama, John M. Starr, Mark E. Bastin, Joanna M. Wardlaw, Ian J. Deary;
Intelligence (Juli-August 2015)


Brain size is known to correlate with general intelligence (g).
It is unclear which other neuroimaging variables contribute beyond total brain size.
We model multiple brain measures and g in a large sample aged around 73 years.
All brain variables together account for around 20% of variance in g.


People with larger brains tend to score higher on tests of general intelligence (g). It is unclear, however, how much variance in intelligence other brain measurements would account for if included together with brain volume in a multivariable model. We examined a large sample of individuals in their seventies (n = 672) who were administered a comprehensive cognitive test battery. Using structural equation modelling, we related six common magnetic resonance imaging-derived brain variables that represent normal and abnormal features—brain volume, cortical thickness, white matter structure, white matter hyperintensity load, iron deposits, and microbleeds—to g and to fluid intelligence. As expected, brain volume accounted for the largest portion of variance (~ 12%, depending on modelling choices). Adding the additional variables, especially cortical thickness (+~ 5%) and white matter hyperintensity load (+~ 2%), increased the predictive value of the model. Depending on modelling choices, all neuroimaging variables together accounted for 18–21% of the variance in intelligence. These results reveal which structural brain imaging measures relate to g over and above the largest contributor, total brain volume. They raise questions regarding which other neuroimaging measures might account for even more of the variance in intelligence.

Freitag, 29. Mai 2015

Elastic energy storage in the shoulder and the evolution of highspeed throwing in Homo

Elastic energy storage in the shoulder and the evolution of highspeed throwing in Homo
Neil T. Roach1, Madhusudhan Venkadesan, Michael J. Rainbow, and Daniel E. Liebermann (2013)


Although some primates, including chimpanzees, throw objects occasionally, only humans regularly throw projectiles with high speed and great accuracy. Darwin noted that humans’ unique throwing abilities, made possible when bipedalism emancipated the arms, enabled foragers to effectively hunt using projectiles. However, there has been little consideration of the evolution of throwing in the years since Darwin made his observations, in part because of a lack of evidence on when, how, and why hominins evolved the ability to generate high-speed throws. Here, we show using experimental studies of throwers that human throwing capabilities largely result from several derived anatomical features that enable elastic energy storage and release at the shoulder. These features first appear together approximately two million years ago in the species Homo erectus. Given archaeological evidence that suggests hunting activity intensified around this time, we conclude that selection for throwing in order to hunt likely played an important role in the evolution of the human genus.

[The Evolution of Throwing]

Valuable Knowledge:

Knowledge that tells us something about the future / that allows us to predict future events at a better than chance level.

Dienstag, 26. Mai 2015

Sex differences in human gregariousness

Sex differences in human gregariousness 
Joyce F. Benenson​, Sandra Stella, Anthony Ferranti (2015)


Research on human sociality rarely includes kinship, social structure, sex, and familiarity, even though these variables influence sociality in non-human primates. However, cross-cultural ethnographic and observational studies with humans indicate that, beginning after age 5 years, males and females form differing social structures with unrelated individuals in a community. Specifically, compared with females, human males exhibit greater tolerance for and form larger, interconnected groups of peers which we term “gregariousness.” To examine sex differences in gregariousness early in life when children first interact with peers without adult supervision, 3- to 6-year-old children were given the choice to enter one of three play areas: an empty one, one with an adult, or one with a familiar, same-sex peer. More males than females initially chose the play area with the same-sex peer, especially after age 5 years. Sex differences in gregariousness with same-sex peers likely constitute one facet of human sociality.

[See also: Warriors and Worriers: The Survival of the Sexes (2014)]

Dienstag, 19. Mai 2015

Sexual selection protects against extinction

Sexual selection protects against extinction
Alyson J. Lumley, Łukasz Michalczyk, James J. N. Kitson, Lewis G. Spurgin, Catriona A. Morrison, Joanne L. Godwin, Matthew E. Dickinson, Oliver Y. Martin, Brent C. Emerson, Tracey Chapman & Matthew J. G. Gage (2015)


Reproduction through sex carries substantial costs, mainly because only half of sexual adults produce offspring. It has been theorized that these costs could be countered if sex allows sexual selection to clear the universal fitness constraint of mutation load. Under sexual selection, competition between (usually) males and mate choice by (usually) females create important intraspecific filters for reproductive success, so that only a subset of males gains paternity. If reproductive success under sexual selection is dependent on individual condition, which is contingent to mutation load, then sexually selected filtering through ‘genic capture’ could offset the costs of sex because it provides genetic benefits to populations. Here we test this theory experimentally by comparing whether populations with histories of strong versus weak sexual selection purge mutation load and resist extinction differently. After evolving replicate populations of the flour beetle Tribolium castaneum for 6 to 7 years under conditions that differed solely in the strengths of sexual selection, we revealed mutation load using inbreeding. Lineages from populations that had previously experienced strong sexual selection were resilient to extinction and maintained fitness under inbreeding, with some families continuing to survive after 20 generations of sib × sib mating. By contrast, lineages derived from populations that experienced weak or non-existent sexual selection showed rapid fitness declines under inbreeding, and all were extinct after generation 10. Multiple mutations across the genome with individually small effects can be difficult to clear, yet sum to a significant fitness load; our findings reveal that sexual selection reduces this load, improving population viability in the face of genetic stress.

[via Steve Stewart Williams]

Samstag, 16. Mai 2015

The evolution of foresight: What is mental time travel, and is it unique to humans?

The evolution of foresight: What is mental time travel, and is it unique to humans?
Thomas Suddendorf and Michael C. Corballis (2007)


In a dynamic world, mechanisms allowing prediction of future situations can provide a selective advantage. We suggest that memory systems differ in the degree of flexibility they offer for anticipatory behavior and put forward a corresponding taxonomy of prospection. The adaptive advantage of any memory system can only lie in what it contributes for future survival. The most flexible is episodic memory, which we suggest is part of a more general faculty of mental time travel that allows us not only to go back in time but also to foresee, plan, and shape virtually any specific future event. We review comparative studies and find that, in spite of increased research in the area, there is as yet no convincing evidence for mental time travel in nonhuman animals. We submit that mental time travel is not an encapsulated cognitive system, but instead comprises several subsidiary mechanisms. A theater metaphor serves as an analogy for the kind of mechanisms required for effective mental time travel. We propose that future research should consider these mechanisms in addition to direct evidence of future-directed action. We maintain that the emergence of mental time travel in evolution was a crucial step toward our current success. 

Mental time travel and the shaping of the human mind

Mental time travel and the shaping of the human mind 
Thomas Suddendorf, Donna Rose Addis and Michael C. Corballis (2009)


Episodic memory, enabling conscious recollection of past episodes, can be distinguished from semantic memory, which stores enduring facts about the world. Episodic memory shares a core neural network with the simulation of future episodes, enabling mental time travel into both the past and the future. The notion that there might be something distinctly human about mental time travel has provoked ingenious attempts to demonstrate episodic memory or future simulation in non-human animals, but we argue that they have not yet established a capacity comparable to the human faculty. The evolution of the capacity to simulate possible future events, based on episodic memory, enhanced fitness by enabling action in preparation of different possible scenarios that increased present or future survival and reproduction chances. Human language may have evolved in the first instance for the sharing of past and planned future events, and, indeed, fictional ones, further enhancing fitness in social settings.

Are Animals Stuck in Time?

Are Animals Stuck in Time?
William A. Roberts (2002)


People can time travel cognitively because they can remember events having occurred at particular times in the past (episodic memory) and because they can anticipate new events occurring at particular times in the future. The ability to assign points in time to events arises from human development of a sense of time and its accompanying time-keeping technology. The hypothesis is advanced that animals are cognitively stuck in time; that is, they have no sense of time and thus have no episodic memory or ability to anticipate long-range future events. Research on animals’ abilities to detect time of day, track short time intervals, remember the order of a sequence of events, and anticipate future events are considered, and it is concluded that the stuck-in-time hypothesis is largely supported by the current evidence.

Donnerstag, 14. Mai 2015

know thyself

hbd chick:
(A) know thyself
(B) me, myself, and i

Mental Time Travel and the Evolution of the Human Mind

Mental Time Travel and the Evolution of the Human Mind
Thomas Suddendorf (1997)


We argue that the human ability to travel mentally in time constitutes a discontinuity between ourselves and other animals. Mental time travel comprises the mental reconstruction of personal events from the past (episodic memory) and the mental construction of possible events in the future. It is not an isolated module, but depends on the sophistication of other cognitive capacities, including self-awareness, meta-representation, mental attribution, understanding the perception-knowledge relationship, and dissociation of imagined mental states from one's present mental state. These capacities are also important aspects of so-called "theory of mind", and they appear to mature in children at around age four. Furthermore, mental time travel is generative, involving the combination and recombination of familiar elements, and in this respect may have been a precursor to language. Current evidence, although indirect or based on anecdote rather than on systematic study, suggests that nonhuman animals, including the great apes, are confined to a "present" that is limited by their current drive states. In contrast, mental time travel by humans is relatively unconstrained, and allows a more rapid and flexible adaptation to complex, changing environments than is afforded by instincts or conventional learning. Past and future events loom large in much of human thinking, giving rise to cultural, religious, and scientific concepts about origins, destiny, and time itself.

[See also: Publications of Thomas Suddendorf]

Mate Choice:

Evolutionary Psychology cares much about mate choice. E.g. according to EP it makes a difference if you choose an intelligent or a stupid mate, a beautiful or an ugly mate, an agreeable or a disagreeable mate, etc. But until now EP doesn't care much about the genetic distance between mates. So my personal hypothesis would be: the genetic distance of mates matters, both on an individual and on a group level (also see: hbd chick). Probably EP would be much more interesting, if it would focus more strongly on questions about outbreeding and inbreeding (and I don't mean just incest avoidance by that).

Sonntag, 10. Mai 2015

Waist-to-Hip Ratio across Cultures: Trade-Offs between Androgen- and Estrogen-Dependent Traits

Waist-to-Hip Ratio across Cultures: Trade-Offs between Androgen- and Estrogen-Dependent Traits
Elizabeth Cashdan (2008)


A gynoid pattern of fat distribution, with small waist and large hips (low waist-to-hip ratio, or WHR) holds significant fitness benefits for women: women with a low WHR of about 0.7 are more fecund, are less prone to chronic disease, and (in most cultures) are considered more attractive. Why, then, do nearly all women have a WHR higher than this putative optimum? Is the marked variation in this trait adaptive? This paper first documents the conundrum by showing that female WHR, especially in non-Western populations, is higher than the putative optimum even among samples that are young, lean, and dependent on traditional diets. The paper then proposes compensating benefits to a high WHR that can explain both its prevalence and variation in the trait. The evidence indicates that the hormonal profile associated with high WHR (high androgen and cortisol levels, low estrogens) favors success in resource competition, particularly under stressful and difficult circumstances, even though this carries fitness costs in fecundity and health. Adrenal androgens, in particular, may play an important role in enabling women to respond to stressful challenges.

Ethnocentrism and Xenophobia: A Cross-Cultural Study

Ethnocentrism and Xenophobia: A Cross-Cultural Study
Elizabeth Cashdan (2001)

"The cross-cultural data analyzed here provide no support for the proposition that out-group hostility is a necessary concomitant of in-group loyalty."

Freitag, 8. Mai 2015

Too Materialistic to Get Married and Have Children?

Too Materialistic to Get Married and Have Children? 
Norman P. Li , Amy J. Y. Lim, Ming-Hong Tsai, Jiaqing O (2015)


We developed new materials to induce a luxury mindset and activate materialistic values, and examined materialism’s relationship to attitudes toward marriage and having children in Singapore. Path analyses indicated that materialistic values led to more negative attitudes toward marriage, which led to more negative attitudes toward children, which in turn led to a decreased number of children desired. Results across two studies highlight, at the individual level, the tradeoff between materialistic values and attitudes toward marriage and procreation and suggest that a consideration of psychological variables such as materialistic values may allow for a better understanding of larger-scale socioeconomic issues including low fertility rates among developed countries. We discuss implications and describe how psychological factors relating to low fertility fit within evolutionary mismatch and life history theory frameworks.

Donnerstag, 7. Mai 2015

Sex Differences in Sports Interest and Motivation: An Evolutionary Perspective

Sex Differences in Sports Interest and Motivation: An Evolutionary Perspective -> pdf
Robert O. Deaner, Shea M. Balish, and Michael P. Lombardo (2015)


Although girls and women in many societies avidly participate in sports, they have been traditionally underrepresented compared with boys and men. In this review, we address the apparent sex differences in sports interest and motivation from an evolutionary perspective. First, we demonstrate that females’ underrepresentation generally reflects lesser interest, not merely fewer opportunities for engagement. Moreover, there is mounting evidence that male and female athletes generally differ in their motivation, specifically their competitiveness and risk taking. Second, we examine the functional explanations for sports. We argue that the courtship display hypothesis applies mainly to females; the spectator lek hypothesis applies chiefly to males; and that 2 other hypotheses—the allying with coalitions hypothesis and the development of skills hypothesis—are important for both females and males. Third, we explore the proximate causes for the sex differences in sports interest and motivation. We show that although there is compelling evidence that prenatal hormones contribute, the evidence that socialization plays a role remains equivocal. We conclude by discussing key findings and identifying areas for further research.

Dienstag, 5. Mai 2015

The Earth Is Round (p < .05)

The Earth Is Round (p < .05)
Cohen, Jacob (1994)


After 4 decades of severe criticism, the ritual of null hypothesis significance testing (mechanical dichotomous decisions around a sacred .05 criterion) still persists. This article reviews the problems with this practice, including near universal misinterpretation of p as the probability that H₀ is false, the misinterpretation that its complement is the probability of successful replication, and the mistaken assumption that if one rejects H₀ one thereby affirms the theory that led to the test. Exploratory data analysis and the use of graphic methods, a steady improvement in and a movement toward standardization in measurement, an emphasis on estimating effect sizes using confidence intervals, and the informed use of available statistical methods are suggested. For generalization, psychologists must finally rely, as has been done in all the older sciences, on replication.

Berlin two months after WW2:

[via RT]

Montag, 4. Mai 2015

Hypothesentestung und Moralphilosophie:

Analog zur statistischen Hypothesentestung ließen sich moralphilosophische Hypothesen folgenderweise beschreiben:

(A) Null-Hypothese / Unwert-Vermutung / Wertlosigkeitsvermutung

(B) Alternativ-Hypothese / Wert- bzw. Widerwertigkeitsvermutung

Ein Nihilist / ein "Alles-Verneiner" begeht exzessiv beta-Fehler, indem er jede Wert-Vermutung zugunsten einer Wertlosigkeits-Vermutung / einer Vermutung von Wert-Neutralität verwirft.

Demgegenüber begeht der "Alles-Bejaher" exzessiv alpha-Fehler, indem er jede Vermutung von Wertneutralität zugunsten einer Wertvermutung verwirft. So kann es bspw. dazu kommen, dass ein gläubiger Mensch einen Erdbeben, eine Seuche, etc., als eine gerechte Strafe Gottes bejaht. Oder das ein Filmkonsument/Theaterkonsument jeden Film/jedes Theaterstück indiskriminatorisch als wertvoll ansieht.

So gibt es zum einen Menschen, die sich schwer tun, auch wahrhaft Wertvolles als wertvoll zu erkennen, zum anderen solche, die nur ungenügend über das Vermögen verfügen, die Wertlosigkeit von Wertlosem einzusehen.

“Doubt is our Product”

[Regarding the acquisition of knowledge there are two (negative) extremes, that could be labeled as (A) illusory uncertainty, and (B) illusory certainty. People can suffer (A) from an overdose of skepticism or (B) from a complete lack of skepticism. According to Peter Hofstätter, critics are especially prone to commit beta errors.]

Reckoning with Risk, Gerd Gigerenzer (2002):

The United States is home to thousands of trade associations promoting everything from asbestos to zinc. The Beer Institute defends brewers against claims that drunk driving causes car accidents. The Asbestos Information Association protects citizens from their “fiber phobia.” The Global Climate Coalition represents scientists who question the evidence for global warming. Washington, D.C., alone, is home to 1,700 such trade associations. Estimates indicate that more than $1 billion is spent by such organizations every year on “image advertising” and “issues management.” Trade associations have become active in the manufacture of knowledge and ignorance. Consider, as an example, the Tobacco Institute's “spin” on the hazards of cigarette smoking.

At the beginning of the twentieth century, lung cancer was an exceptionally rare type of cancer—so rare that Isaac Adler, who wrote the first book-length medical review on lung cancer, apologized for writing about such an uncommon and insignificant disease. By the end of the twentieth century, lung cancer had become the most frequent cause of cancer deaths worldwide. Why? At the beginning of the century, cigarette smoking was rare; people smoked pipes and cigars. Smoking cigars causes different kinds of cancer than smoking cigarettes does. To take an example, Sigmund Freud developed cancer of the mouth as a result of his heavy cigar smoking. The cancer cast a shadow over the last 16 years of his life, causing him continuous pain and discomfort and requiring some 30 operations to remove cancerous and precancerous growths.
Cigarettes first became popular during World War I. Unlike cigar and pipe smoke, cigarette smoke is generally inhaled, exposing lung tissue to irritants. The link between cigarette smoking and lung cancer was first demonstrated by German researchers in the 1920s and 1930s but was largely ignored in America, possibly because this research was associated with the Nazis. In the early 1950s, however, a consensus developed in the American scientific community that cigarettes are a major source of illness, including lung cancer. By the mid-1950s, there was strong evidence that a two-pack-a-day smoker lived, on average, about seven years fewer than a nonsmoker. Most scientists came to agree that tobacco kills about 400,000 Americans every year and that tobacco is the cause of 80 percent to 90 of lung cancers.
The Tobacco Institute was founded in 1958 as an offshoot of the Council for Tobacco Research, which was established by tobacco manufacturers, growers, and warehouse owners. Since then, it has argued the case for cigarette “safety” by creating doubt in the public mind about the hazards of smoking. In the 1960s, spokesmen tried to undermine and distract from the growing consensus in the scientific community. For instance, they asserted that the link between cigarettes and cancer was “merely statistical,” that the evidence was uncertain and the conclusions premature, and that there might be a gene that both leads to smoking and predisposes certain people to developing cancer. In 1962, a Gallup survey found that only 38 percent of American adults knew that cigarettes cause lung cancer. Although many physicians quit smoking after the Surgeon General's Report in 1964 made it clear that cigarettes are a major cause of illness, many members of the public remained under the impression that the question about the effects of smoking on health was still open. The silence in popular magazines about the hazards of smoking played a crucial role in maintaining public ignorance; cigarette advertisers discouraged magazine publishers from covering the topic of smoking hazards. A 1978 article in the Columbia Journalism Review noted that it could not find a single article in a leading national magazine that had discussed the health effects of smoking in the last seven years. The less sophisticated, popular press was more straightforward. A headline in a 1968 National Enquirer read: “Most Medical Authorities Agree, Cigarette Lung Cancer Is Bunk: 70 Million Americans Falsely Alarmed.” Much later, in 1989, the Surgeon General's Report explicitly linked the tobacco lobby's suppression of media coverage to the general public's ignorance of the nature and extent of the hazards of smoking.
More recently, the Tobacco Institute has tried to challenge evidence of the hazards of “passive smoking” or “secondhand smoke.” Strong evidence of the negative health effects of breathing smoke from others' cigarettes emerged in the 1980s, when Tokyo's National Cancer Center Research Institute showed that lung cancer was twice as common among the nonsmoking wives of smokers as among those of nonsmokers. In the 1990s, the Environmental Protection Agency released data indicating that secondhand smoke was responsible for 20 percent of all lung cancer deaths among nonsmokers, that is, for the deaths of about 3,000 Americans a year. The Tobacco Institute dismissed this study as “characterized by a preference for political correctness over sound science.”
The case of the tobacco lobby epitomizes the manufacture of ignorance and confusion. Its efforts at obfuscation shifted constantly; as soon as one argument from the tobacco lobby was discredited, new arguments were constructed to engender fresh confusion. Their arguments and slogans evolved in the following way:
Smoking doesn't hurt your health; it's safe.
OK, smoking may or may not hurt your health, but the scientific evidence is still insufficient and inconclusive.
OK, the evidence is conclusive that smoking does cause lung cancer, but we didn't know until now.
OK, we knew, but we didn't know that nicotine was addictive.
OK, we knew that nicotine was addictive when we added chemicals to cigarettes to make nicotine enter the bloodstream faster, but this was long ago. Today we have low-tar and low-nicotine cigarettes.
OK, low-tar and low-nicotine cigarettes do not actually reduce the risk of lung cancer, but this is people's own fault because they now smoke more cigarettes.
OK, it is in our interest that people smoke more, but they smoke more by their own free choice.
A similar sequence of claims has been made to cloud people's minds concerning the risks of passive smoking. As the historian Robert Proctor reports, this goal was privately admitted in an internal document produced by a cigarette company: “Doubt is our product since it is the best means of competing with the ‘body of facts’ that exists in the mind of the general public.”

[Siehe auch: Entscheidungen des praktischen Lebens]

Sonntag, 3. Mai 2015

Does Jamie Foxx suffer from Overconfidence?

The Evolution and Medicine Course Lecture Series by Steven C. Stearns:

1.1 Natural Selection
1.2 Random Evolution
1.3 Mismatch
1.4 Adaptation
1.5 Types of Thinking

2.1 What is a patient?  Ancient History
2.2 What is a patient?  Recent History
2.3 What is a patient?  Genetic Variation for Disease Resistance
2.4 What is a Patient?  Genetic Variation for Ability to Metabolize Drugs
2.5 What is a Patient?  The Human Life History and its Evolution
2.6 What is a patient?  Reaction Norms and Phenotypic Plasticity
2.7 What is a patient?  A Bundle of Tradeoffs
2.8 What is a patient?  Someone Who Ages
2.9 What is a patient?  The Unusual Human Life History
2.10 What is a patient? The Developmental Origins of Disease
2.11 What is a patient? The Microbiome
2.12 What is a patient? Summary

3.1 What is a disease? Introduction
3.2 What is a Disease? Vulnerable vs. Robust Tissues and Organs
3.3 What is a Disease? From Fixed to Adjustable Reactions
3.4 What is a Disease? History and Mismatch

4.1 Defenses: Origins and Costs
4.2 Defenses: Specialized
4.3 Defenses: Key Characteristics
4.4 Defenses: The Major Strategies
4.5 Defenses: Tolerance
4.6 Defenses: Evolution of the Vertebrate Immune System
4.7 Defenses: More Detail on the Vertebrate Immune Response
4.8 Defenses: Managing the Microbiome -- Symbionts vs. Pathogens

5.1 Pathogen Evolution: Virulence
5.2 Pathogen Evolution: Evasion of Host Defenses
5.3 Pathogen Evolution: Antibiotic Resistance
5.4 Pathogen Evolution: Evolution-Proof Therapies

6.1 The Evolution of Reproduction: Mammalian Reproduction
6.2 The Evolution of Reproduction: Invasive Placentas
6.3 The Evolution of Reproduction: Evolutionary Conflict
6.4 The Evolution of Reproduction: Genomic Conflict and Mental Health
6.5 The Evolution of Reproduction: Menstruation and Menopause
6.6 The Evolution of Reproduction: Upright Posture and Childbirth

7.1 Cancer as an Evolutionary Process: Introduction
7.2 Cancer as an Evolutionary Process: Why we are Susceptible
7.3 Cancer as an Evolutionary Process: Clonal Evolution
7.4 Cancer as an Evolutionary Process: Phylogenetics
7.5 Cancer as an Evolutionary Process: Immune Evasion
7.6 Cancer as an Evolutionary Process: Managing Chemotherapy

Freitag, 1. Mai 2015

Speed and Accuracy (Part 2):

[See also: Speed and Accuracy (Part 1)]

Dart - World Champions:
(years rounded, month of birth/championship not considered)

2000 Ted Hankey                     (32 years old)
2001 John Walton                    (40 years)
2002 Tony David                      (35 years)
2003 Raymond van Barneveld (36 years)
2004 Andy Fordham                 (42 years)
2005 Raymond van Barneveld (38 years)
2006 Jelle Klaasen                   (22 years)
2007 Martin Adams                  (51 years)
2008 Mark Webster                  (25 years)
2009 Ted Hankey                     (41 years)
2010 Martin Adams                  (54 years)
2011 Martin Adams                  (55 years)
2012 Christian Kist                   (26 years)
2013 Scott Waites                    (36 years)
2014 Stephen Bunting              (29 years)
2015 Scott Mitchell                   (45 years)

[Dart championships primarily "measure" throwing accuracy.]
[Sex differences in throwing speed are much larger than sex differences in throwing accuracy. (K. Browne; Thomas and French) However, the size of the sex difference in throwing accuracy is still large.]
[Another interesting topic: >Speed and Endurance<]