Montag, 4. September 2017

The Hajnal Line and Gene-Culture Coevolution in Northwest Europe

The Hajnal Line and Gene-Culture Coevolution in Northwest Europe
Peter Frost (August 2017)


Abstract

North and west of a line running from Trieste to St. Petersburg, social relations have long conformed to the Western European Marriage Pattern, i.e., men and women marry relatively late; many people never marry; children usually leave the nuclear family to form new households, and households often have non-kin members. This pattern goes back at least to the thirteenth century and perhaps to prehistoric times. I argue that this environment of weaker kinship caused northwest Europeans to create communities based on shared moral rules, rather than shared kinship. Community members enforced these rules by monitoring not only the behavior of other members but also their own behavior and even their own thoughts. Initially, this new mindset did not have a genetic basis. Individuals acquired it within the bounds of phenotypic plasticity. Over time, however, a genetic basis would have developed through the survival and reproduction of individuals who were better at being socially independent, at obeying universal rules, at monitoring other community members, and at self-monitoring, self-judging, and self-punishing. These psychological adaptations—independent social orientation, universal rule adherence, affective empathy, guilt proneness—are moderately to highly heritable. Although they are complex, they required only minor evolutionary changes to evolve out of mechanisms that were already present but limited to specific behavioral contexts. Affective empathy, for instance, is a species-wide trait but usually confined to relations with close kin, particularly between a mother and her young children. An evolutionary scenario is proposed, and two questions discussed. Are these mental traits too complex to have evolved over a span of 30 to 300 generations? Are they too altruistic to be sustainable?


Peter Frost: "I'm back to blogging, perhaps a new column every two weeks."

Samstag, 5. August 2017

Studying through Active Recall


The lifestyle-design community

Why Skills Trump Passion
Cal Newport (2012)


"The more I studied examples of control, the more I encountered people who had made ... mistakes. Jane’s story, for example, is just one of many from the growing lifestyle-design community. This movement argues that you don’t have to live life by other people’s rules. It encourages its followers to design their own path through life—preferably one that’s exciting and enjoyable to live. It’s easy to find examples of this philosophy in action, because many of its disciples blog about their exploits.

At a high level, of course, there’s nothing wrong with this philosophy. The author Timothy Ferriss, who coined the term “lifestyle design,” is a fantastic example of the good things this approach to life can generate (Ferriss has more than enough career capital to back up his adventurous existence). But if you spend time browsing the blogs of lesser-known lifestyle designers, you’ll begin to notice the same red flags again and again: A distressingly large fraction of these contrarians, like Jane, skipped over the part where they build a stable means to support their unconventional lifestyle. They assume that generating the courage to pursue control is what matters, while everything else is just a detail that is easily worked out.

One such blogger I found, to give another example from among many, quit his job at the age of twenty-five, explaining, “I was fed up with living a ‘normal’ conventional life, working 9–5 for the man [and] having no time and little money to pursue my true passions… so I’ve embarked on a crusade to show you and the rest of the world how an average Joe… can build a business from scratch to support a life devoted to living ‘The Dream.’ ” The “business” he referenced, as is the case with many lifestyle designers, was his blog about being a lifestyle designer. In other words, his only product was his enthusiasm about not having a “normal” life. It doesn’t take an economist to point out there’s not much real value lurking there. Or, put into our terminology, enthusiasm alone is not rare and valuable and is therefore not worth much in terms of career capital. This lifestyle designer was investing in a valuable trait but didn’t have the means to pay for it.

Not surprisingly, things soon turned bleak on this fellow’s blog. After three months of posting several times a week about how to fund an unconventional life through blogging—even though he wasn’t making any money himself from his own site—some frustration crept into his writing. In one post, he says, with evident exasperation, “What I noticed is that [readers] come and go. I’ve put in the hard yards, writing quality posts and finding awesome people… but alas many of [you] just come and go. This is as annoying as trying to fill up a bucket with water that has a bunch of holes in it.” He then goes on to detail his ten-point plan for building a more stable audience. The plan includes steps such as “#2. Bring the ENERGY” and “#4. Shower Your Readers with Appreciation,” but the list still excludes the most important step of all: giving readers content they’re willing to pay for. A few weeks later, the posts on the blog stopped. By the time I found it, there hadn’t been a single new post in over four months.

This story provides another clear example of the first control trap: If you embrace control without capital, you’re likely to end up like Jane, Lisa, or our poor frustrated lifestyle designer—enjoying all the autonomy you can handle but unable to afford your next meal. This first trap, however, turns out to be only half of the story of why control can be a tricky trait to acquire. ...[E]ven after you have the capital required to acquire real control, things remain difficult, as it’s exactly at this point that people begin to recognize your value and start pushing back to keep you entrenched in a less autonomous path."

[Also see: Scott Adams on Passion]

Dienstag, 11. Juli 2017

Brain volume and intelligence: The moderating role of intelligence measurement quality

Brain volume and intelligence: The moderating role of intelligence measurement quality
Gilles E. Gignac, Timothy C. Bates (2017)



Highlights

Correlation between brain volume and IQ in healthy adults is r ≈ .40.
The importance of correcting correlations for range restriction is demonstrated.
Intelligence measurement quality was a moderator of the brain volume/IQ effect.
Fair, good, and excellent measures of IQ yielded correlations of .23, .32, and .39.
p-Curve analysis indicated the significant results in the area likely not due to p-hacking.


Abstract

A substantial amount of empirical research has estimated the association between brain volume and intelligence. The most recent meta-analysis (Pietschnig, Penke, Wicherts, Zeiler, & Voracek, 2015) reported a correlation of .24 between brain volume and intelligence – notably lower than previous meta-analytic estimates. This headline meta-analytic result was based on a mixture of samples (healthy and clinical) and sample correlations not corrected for range restriction. Additionally, the role of IQ assessment quality was not considered. Finally, evidential value of the literature was not formally evaluated. Based on the results of our meta-analysis of the Pietschnig et al.'s sample data, the corrected correlation between brain volume and intelligence in healthy adult samples was r = .31 (k = 32; N = 1758). Furthermore, the quality of intelligence measurement was found to moderate the effect between brain volume and intelligence (b = .08, p = .028). Investigations that used ‘fair’, ‘good’, and ‘excellent’ measures of intelligence yielded corrected brain volume and intelligence correlations of .23 (k = 9; N = 547), .32 (k = 10; N = 646), and .39 (k = 13; N = 565), respectively. The Henmi/Copas adjusted confidence intervals, the p-uniform results, and the p-curve results failed to suggest evidence of publication bias and/or p-hacking. The results were interpreted to suggest that the association between in vivo brain volume and intelligence is arguably best characterised as r ≈ .40. Researchers are encouraged to consider intelligence measurement quality in future meta-analyses, based on the guidelines provided in this investigation.

Sonntag, 9. Juli 2017

>In English, the words "explore" and "exploit" come loaded with completely opposite connotations. But to a computer scientist, these words have much more specific and neutral meanings. Simply put, exploration is gathering information, and exploitation is using the information you have to get a known good result.<

B. Christian & T. Griffiths

[Also see ...]

Creativity and Genius:

"Creativity and genius are unrelated to g except that a person’s level of g acts as a threshold variable below which socially significant forms of creativity are highly improbable. This g threshold is probably at least one standard deviation above the mean level of g in the general population. Besides the traits that Galton thought necessary for “ eminence” (viz., high ability, zeal, and persist­ence), genius implies outstanding creativity as well. Though such exceptional creativity is conspicuously lacking in the vast majority of people who have a high IQ, it is probably impossible to find any creative geniuses with low IQs. In other words, high ability is a necessary but not sufficient condition for the emergence of socially significant creativity. Genius itself should not be confused with merely high IQ, which is what we generally mean by the term “ gifted” (which also applies to special talents, such as music and art). True creativity involves more than just high ability. It is still uncertain what this is ..."

The g factor (1998)
Arthur R. Jensen 

Why are there so many explanations for primate brain evolution?

Why are there so many explanations for primate brain evolution?
R. I. M. Dunbar, Susanne Shultz (2017)


Abstract

The question as to why primates have evolved unusually large brains has received much attention, with many alternative proposals all supported by evidence. We review the main hypotheses, the assumptions they make and the evidence for and against them. Taking as our starting point the fact that every hypothesis has sound empirical evidence to support it, we argue that the hypotheses are best interpreted in terms of a framework of evolutionary causes (selection factors), consequences (evolutionary windows of opportunity) and constraints (usually physiological limitations requiring resolution if large brains are to evolve). Explanations for brain evolution in birds and mammals generally, and primates in particular, have to be seen against the backdrop of the challenges involved with the evolution of coordinated, cohesive, bonded social groups that require novel social behaviours for their resolution, together with the specialized cognition and neural substrates that underpin this. A crucial, but frequently overlooked, issue is that fact that the evolution of large brains required energetic, physiological and time budget constraints to be overcome. In some cases, this was reflected in the evolution of ‘smart foraging’ and technical intelligence, but in many cases required the evolution of behavioural competences (such as coalition formation) that required novel cognitive skills. These may all have been supported by a domain-general form of cognition that can be used in many different contexts.