In my experience most scientists are not too clear on the details of intelligence testing, perhaps because the whole area is somewhat in ill repute (except when you want to brag about your own SAT/GRE score!). This despite the fact that the profession of science is skewed toward the right end of the intelligence bell curve. Steve Hsu, a physicist at the University of Oregon (and someone I’ve known for a while in the interests of “full disclosure”) has a nice presentation up in PDF format which summarizes the major points of interest in this area. Worth a skim if you are unfamiliar. Additionally he alludes to future directions in the study of the genetic basis of intelligence using genomics. Here’s his abstract:
I begin with a brief review of psychometric results concerning intelligence (sometimes referred to as the g factor, or IQ). The main results concern the stability, validity (predictive power) and heritability of adult IQ. Next, I discuss ongoing Genome Wide Association Studies which investigate the genetic basis of intelligence. Due mainly to the rapidly decreasing cost of sequencing (currently below $5k per genome), it is likely that within the next 5-10 years we will identify genes which account for a significant fraction of total IQ variation. Finally, I end with an analysis of possible near term genetic engineering for intelligence.
This talk is aimed at physicists and should be accessible even to those with no specialized background in psychology or biology.
Also, in case you are skeptical, Steve is quite aware of the difficulties with the enterprise which he outlines in the presentation assuming that the genetic architecture of intelligence is as he assumes. As sequencing gets cheaper and the sample size of full genomes hits the tens of thousands someone will tackle this, so he and his colleagues figured why not now?
Judging by some of the amusing search queries I find every Friday people have a wide range of tastes and fetishes when it comes to pornography. From what I can tell the realized phenotypic interval in mate choice is less varied and eye-opening, but exists nonetheless. Why? Is there a rhyme or reason, or is it simply random chance and the necessity of the biological clock ticking? These are not issues which aren’t discussed or mooted thoroughly regularly. The popular science literature is littered with hypotheses from social and evolutionary psychology. How else could you have a books such as The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature and Survival of the Prettiest: The Science of Beauty. This is sexy science by definition. Not Physics Letters.
There are three broad issues which have interested me in the domain of attraction and evolution. First, what is the character of cultural universals of beauty rooted in biological preferences? Second, what is the character of cultural variation in beauty rooted in contingencies or local conditions? And third, what are the genetic and non-genetic factors in individual mate preference? In this post I’ll focus on the last. Not to put a fine point on it: are you born with a “type,” or is your “type” a matter of chance and necessity after you are born? An interesting twist on the second issue is that one phenomenon which falls into the “not born” but biological category is the process of sexual imprinting. For example, you may exhibit attraction to individuals who resemble your opposite sex parent.* The clear connection to the presumed “Oedipus complex” of this probably explains it prominence.
A new paper in The American Naturalist aims to examine the question of realized variation individual preferences with a huge sample of twins, monozygotic and dizygotic. By realized, I mean that they focus on the people with whom you actually pair up, not your ideal avowed preference. Variation in human mate choice: simultaneously investigating heritability, parental influence, sexual imprinting, and assortative mating:
This is a datum which you can dine out on, The Bias You Didn’t Expect:
It turns out that legal realism is totally wrong. It’s not what the judge had for breakfast. It’s how recently the judge had breakfast. A a new study (media coverage) on Israeli judges shows that, when making parole decisions, they grant about 65% after meal breaks, and almost all the way down to 0% right before breaks and at the end of the day (i.e. as far from the last break as possible). There’s a relatively linear decline between the two points.
Ms. Aoi, and others like her, are the secret of a winning formula stumbled upon by Maxima Pictures, the production house where Mr. Hidayat is an executive producer. For two years, Maxima has made some of Indonesia’s most popular domestic films based on a simple premise: that many in Muslim-majority Indonesia will pay to see foreign porn stars perform — clothed — in local films. Just don’t expect Indonesians to own up to it.
“We’re hypocrites,” said Mr. Hidayat, who is a Muslim. “People know who they are, but they won’t admit it. It’s a love-hate thing.”
This sort of “counter-intuitive” behavior makes total sense in light of the work reported in Paul Bloom’s How Pleasure Works: The New Science of Why We Like What We Like. People consume in a particular context. The hedonic experience can’t be isolated from its history and the prior facts (and expectations) you bring into it. This sort of insight is essential when we start talking about utilitarianism as if it’s a simple calculus.
One of the interesting and robust nuggets from behavior genetics is that heritability of psychological traits increases as one ages. Imagine for example you have a cohort of individuals you follow over their lives. At the age of 1 the heritability of I.Q. may be ~20%. This means that ~20% of the variation in the population of I.Q. explained by variation in the genes of the population. More concretely, you would only expect a weak parent-offspring correlation in I.Q. in this sample. At the age of 10 the heritability of I.Q. in the same sample may be ~40%, and in mature adulthood it may rise to ~80% (those are real numbers which I’ve borrowed from Robert Plomin). Many people find this result rather counterintuitive. How can a trait like intelligence become “more genetic”?
Remember that I’m talking about heritability here, not an ineffable “more” or “less” quantum of “genetic” aspect of a trait. In other words: does variation in genes due to different parental backgrounds matter for a trait? Second, the nature of psychological traits is somewhat slippery and plastic. As I’ve noted before the correlation between a score on a 10-world vocabulary test and general intelligence is pretty good. You can expect people with high scores on the vocabulary test to have higher I.Q.’s than those who have low scores. But if you take an individual and lock them in a room without human contact for their first 15 years, they are unlikely to exhibit any such correspondence. You don’t have to be a rocket scientist to understand why. Quantitative behavior genetic traits are complex and are subject to a host of background conditions, and express themselves in an environmental context.
I approached Sheril Kirshenbaum’s The Science of Kissing: What Our Lips Are Telling Us with some trepidation and excitement. The former is a consequence of my hypochondria and its associated germophobia. I have no aversion to kissing in my own life (apologies for divulging personal information), but I did have some worries about having to read about other humans engaged in such an act of hygienic daring. And yet I was excited because I am interested in multidisciplinary explorations of human behavior. And of course I was familiar with the author’s oeuvre, and was expecting an engaging and wide-ranging exploration of the topic at hand.
I was not disappointed. The Science of Kissing is an intellectual full-court press; every conceivable discipline of relevance is brought into the mix. History, ethnography, ethology, neuroscience, evolutionary biology, physiology, and epidemiology, all receive attention, to name just a few of the more prominent lenses which the author fits over the course of the narrative. In other words you’re presented with an intellectual buffet. A well rounded meal will require you to sample widely, but if the lack of punctiliousness of Romans in matters of hygiene is not to your taste, you may find a discussion of the latest neuroimaging techniques and their application to matters of behavioral response more to your liking.
A few days Kevin Drum proposed a “Human Nature Top 10.” Here are the criteria:
Not personal pet theories, but aspects of human nature that are (a) widely accepted and relatively noncontroversial among professionals, and (b) underappreciated by most of us. They can come from anywhere: economics, psychology, sociology, politics, anthropology, whatever.
He offers two: loss aversion & regression to the mean. These are excellent. I’ll chip in with two. Mine are probably a touch more tendentious, but I’m going to offer them anyway (I don’t even know what the right terms are, but I think they’re real phenomena which I’ve seen alluded to in the literature):
One of the issues when talking about the effect of environment and genes on behavioral and social outcomes is that the entanglements are so complicated. People of various political and ideological commitments tend to see the complications as problems for the other side, and yet are often supremely confident of the likely efficacy of their predictions based on models which they shouldn’t even been too sure of. That is why cross-cultural studies are essential. Just as psychology has overly relied on the WEIRD nature of data sets, so it is that those interested in social science need to see if their models are robust across cultures (I’m looking at you economists!).
That is why this ScienceDaily headline, Family, Culture Affect Whether Intelligence Leads to Education, grabbed my attention. The original paper is Family Background Buys an Education in Minnesota but Not in Sweden:
Educational attainment, the highest degree or level of schooling obtained, is associated with important life outcomes, at both the individual level and the group level. Because of this, and because education is expensive, the allocation of education across society is an important social issue. A dynamic quantitative environmental-genetic model can help document the effects of social allocation patterns. We used this model to compare the moderating effect of general intelligence on the environmental and genetic factors that influence educational attainment in Sweden and the U.S. state of Minnesota. Patterns of genetic influence on educational outcomes were similar in these two regions, but patterns of shared environmental influence differed markedly. In Sweden, shared environmental influence on educational attainment was particularly important for people of high intelligence, whereas in Minnesota, shared environmental influences on educational attainment were particularly important for people of low intelligence. This difference may be the result of differing access to education: state-supported access (on the basis of ability) to a uniform higher-education system in Sweden versus family-supported access to a more diverse higher-education system in the United States.
Sometimes books advertise themselves very well with their title. The Invisible Gorilla: And Other Ways Our Intuitions Deceive Us is one of those books. Alternatively it could have been titled: “Giving thinking a second chance.” Or, with an eye toward pushing copies: “Why everything Malcolm Gladwell tells you is crap.” And finally, a more highbrow possibility: “Reflection: man’s greatest invention.”
The “hook” for The Invisible Gorilla is the experiment which goes colloquially by the same name. The authors of the book, Christopher Chabris and Daniel Simons, actually wrote the paper Gorillas in our midst: sustained inattentional blindness for dynamic events (though they note that the basic insight goes back to the 1970s). Here’s a YouTube clip illustrating Chabris & Simons’ set up. Despite the eye-catching way the authors grab your attention the core message of The Invisible Gorilla is often very Plain Jane: thinking is hard, it yields real results, and, beware of short-cuts. Many sections of the book read as counterpoints to the counterintuitive defenses of intuition which Malcolm Gladwell presents in Blink: The Power of Thinking Without Thinking (Gladwell as it happens played a key role in popularizing knowledge of “the invisible gorilla” phenomenon). Despite being “sexed” up in the past few decades the defense of intuition, of “gut,” has a long intellectual history. For every Kant there is a Wang Yangming. And yet the borderlands between intuition and deduction, reflex and reflection, can often be gray. I would argue that much of human culture actually emerges from rational extensions of intuition. David Hume famously asserted reason’s slavery to passion, but I think a less grand way of characterizing the nature of different aspects of cognition is that they complement and supplement each other (see How We Decide).
Harvard University psychologist Marc Hauser — a well-known scientist and author of the book “Moral Minds’’ — is taking a year-long leave after a lengthy internal investigation found evidence of scientific misconduct in his laboratory.
The findings have resulted in the retraction of an influential study that he led. “MH accepts responsibility for the error,’’ says the retraction of the study on whether monkeys learn rules, which was published in 2002 in the journal Cognition.
Two other journals say they have been notified of concerns in papers on which Hauser is listed as one of the main authors.
It is unusual for a scientist as prominent as Hauser — a popular professor and eloquent communicator of science whose work has often been featured on television and in newspapers — to be named in an investigation of scientific misconduct. His research focuses on the evolutionary roots of the human mind.
Hauser is a prominent public intellectual. Here’s his Edge page. Obviously problems in some aspects of his work doesn’t necessarily invalidate all his findings, but it doesn’t look good for his credibility. This sort of incident points to the importance of trust within the culture of science. Collaborators and researchers who cited his results are scrambling to make sense of it all. I’ve cited Moral Minds in past posts, but I probably won’t be doing so now.
This post by Neurocritic, Bad News for the Genetics of Personality, is going to get a lot of play. The boy-king of the cognitive neuroscience blogosphere has already smiled upon it, and extended the analysis a bit. The short of it is that one needs to be very skeptical of the idea large effect QTLs in personality genetics. In the post the Neurocritic reviews a paper, A genome-wide association study of Cloninger’s Temperament scales: Implications for the evolutionary genetics of personality, which performed a genome-wide association, and found basically nothing despite a large sample size. I’m not that surprised as genomicists I know have expressed lots of skepticism of previous work in this area. The implication here is that personality may be like height or I.Q., having a genetic component, but not one whose genetic architecture is easy to elucidate with current methods.
Social conservative blogger Rod Dreher points me to this interview of a Left-wing sociologist on the malevolent influence of pornography on modern relationships. She has a book out, Pornland: How Porn has Hijacked our Sexuality. Her conclusion:
To turn this around there needs to be a massive public health awareness campaign. Unless people begin to understand the role pornography is playing in our culture, I can’t see any reason that this won’t get worse, because all of these men who started watching pornography young are going to want more and more. Pornographers themselves say they’re having trouble keeping up with what fans want because they want it so hardcore.
Where is this going to end? I don’t know. What will an 11-year-old boy want 10, 20, or 30 years from now? Nobody knows. The truth is we’ve never brought up a generation of males with hardcore pornography. No one can really say what’s going to happen. What we do know, from how images and media affect people, is that it’s going to increasingly shape the way men think about sex, sexuality, and relationships.
I highly recommend this discussion between Paul Bloom & Robert Wright. The topic under consideration is the psychology of pleasure, as reviewed in Bloom’s new book How Pleasure Works: The New Science of Why We Like What We Like. You can also find out about Bloom’s ideas in this exchange in Slate. The essentialism examined in Descarte’s Baby is being taken for another spin, though with a more precise focus. The bottom line is that pleasure is often contingent on more than proximate empirical sensory input; it depends on what you perceive to be the essence of the object of pleasure, even its history (or more crassly, its price). This truth may make the calculation project of the utilitarian heirs of Gottfried Leibniz pragmatically impossible.
Quotes because you might not find it counterintuitive, Self-Esteem Development From Young Adulthood to Old Age: A Cohort-Sequential Longitudinal Study:
The authors examined the development of self-esteem from young adulthood to old age. Data came from the Americans’ Changing Lives study, which includes 4 assessments across a 16-year period of a nationally representative sample of 3,617 individuals aged 25 years to 104 years. Latent growth curve analyses indicated that self-esteem follows a quadratic trajectory across the adult life span, increasing during young and middle adulthood, reaching a peak at about age 60 years, and then declining in old age. No cohort differences in the self-esteem trajectory were found. Women had lower self-esteem than did men in young adulthood, but their trajectories converged in old age. Whites and Blacks had similar trajectories in young and middle adulthood, but the self-esteem of Blacks declined more sharply in old age than did the self-esteem of Whites. More educated individuals had higher self-esteem than did less educated individuals, but their trajectories were similar. Moreover, the results suggested that changes in socioeconomic status and physical health account for the decline in self-esteem that occurs in old age
As a person well under 60 but slowing walking in that direction I’m pretty heartened by this. On the other hand, I’m one o those people who also tend to think that “self-esteem” is a bit overrated, so I’m not that heartened.
Via Randall Parker
The origin of values and preferences is an unresolved theoretical question in behavioral and social sciences. The Savanna-IQ Interaction Hypothesis, derived from the Savanna Principle and a theory of the evolution of general intelligence, suggests that more intelligent individuals may be more likely to acquire and espouse evolutionarily novel values and preferences (such as liberalism and atheism and, for men, sexual exclusivity) than less intelligent individuals, but that general intelligence may have no effect on the acquisition and espousal of evolutionarily familiar values (for children, marriage, family, and friends). The analyses of the National Longitudinal Study of Adolescent Health (Study 1) and the General Social Surveys (Study 2) show that adolescent and adult intelligence significantly increases adult liberalism, atheism, and men’s (but not women’s) value on sexual exclusivity.
I don’t have access to the paper, but ScienceDaily reports the values. For the NLSY, which surveys teens:
Very liberal IQ = 106
Very conservative IQ = 95
Atheist IQ = 103
Very religious IQ = 97
Since my last post was rather pessimistic, I thought I’d point to something a little more cheerful, Social Scientists Build Case for ‘Survival of the Kindest’:
Researchers at the University of California, Berkeley, are challenging long-held beliefs that human beings are wired to be selfish. In a wide range of studies, social scientists are amassing a growing body of evidence to show we are evolving to become more compassionate and collaborative in our quest to survive and thrive.
In contrast to “every man for himself” interpretations of Charles Darwin’s theory of evolution by natural selection, Dacher Keltner, a UC Berkeley psychologist and author of “Born to be Good: The Science of a Meaningful Life,” and his fellow social scientists are building the case that humans are successful as a species precisely because of our nurturing, altruistic and compassionate traits.
They call it “survival of the kindest.”
“Because of our very vulnerable offspring, the fundamental task for human survival and gene replication is to take care of others,” said Keltner, co-director of UC Berkeley’s Greater Good Science Center. “Human beings have survived as a species because we have evolved the capacities to care for those in need and to cooperate. As Darwin long ago surmised, sympathy is our strongest instinct.”
Human nature is mixed. There’s a bit of Jekyll and Hyde in everyone, and likely to variant extents as well. But empirically we know that human competencies are such that we can scale social organizations to an incredibly complex level. In fact I think evolutionary anthropologists have established with a high degree of certainty that the Hobbesian model of “all against all” is not grounded in the natural history of our species. Rather, we have been a rather groupish lineage for a long time, and recently we have been scaling up the size and complexity of our groups quite a bit.
Relative to atheists, and conventional religious people (though conventional religious people are more delusional than atheists). Tom Rees has more:
Overall, the New Agers were more delusional than the Religious. That was particularly true for belief in witchcraft and telepathy (not shown in the graph). But the New Agers were also more likely to think that people are not what they seem, that they are being persecuted, that electrical devices like computers can control their thoughts, and that their thoughts are ‘echoed back’.
On a mass scale people with orthodox beliefs who are affiliated with institutional religions have more impact because they can organize. But, on a personal level New Agers are often harder to deal with because the weirdness of their beliefs is often hard to anticipate, and they can take a scattershot approach to irrationality, barraging you with a sequence of unrelated bizarre intuitions and claims (in contrast, orthodox religious people have a more stable script of talking points).
The original paper is Is the New Age phenomenon connected to delusion-like experiences? Analysis of survey data from Australia.
Eric Michael Johnson has a post up, Does Taking Birth Control Alter Women’s Sexual Choices?, where he surveys a new paper,Does the contraceptive pill alter mate choice in humans?. Eric notes:
The concern of the researchers is that a woman who gets involved with a guy while on the pill might find that she’s no longer compatible with him once she stops later on in the relationship. Imagine waking up next to your boyfriend, or even your husband, one morning only to discover that you’re just not that into him. While female comedians make such scenarios commonplace in their stand-up routines, Alvergne and Lummaa suggest it could be a reality faced by the modern woman.
There are lots of issues in relationships. Here’s a chart of divorce rates from 1940 to 2000.
Visa announced this spring that spending on Visa debit cards in the United States surpassed credit for the first time in the company’s history. In 2008, debit payment volume was $206 billion, compared with credit volume of $203 billion. MasterCard reported that for the first six months of this year, the volume of purchases on its debit cards increased 4.1 percent, to $160 billion, in the United States. Spending on credit and charge cards sank 14.8 percent, to $233 billion.
“Consumers are rational thinking individuals, and they’re going to shift their behavior in a way that fits with their current economic situation,” said Scott Strumello, an associate with the Auriemma Consulting Group, a Long Island-based payment card advisory firm. “They’re thinking more seriously about it, and many may decide, ‘I’m going to use debit where I can and reserve credit for larger purchases.’ ”
I think really what’s going on here is that people are embracing the pain of paying; when you decouple time of payment from what you’re purchasing that tends to result in more purchase than would otherwise be the case. A perfectly rational individual wouldn’t need to make a distinction between debit and credit, what does it matter if you pay for a latte tomorrow (that is, it comes out of your account tomorrow) vs. the next billing cycle? No, people are rational about the fact that they are irrational. Pay later = buy more, pay tomorrow = buy less. If you want to buy less then heighten the immediacy of the cost.
We hypothesized that religiosity, a set of traits variably expressed in the population, is modulated by neuroanatomical variability. We tested this idea by determining whether aspects of religiosity were predicted by variability in regional cortical volume. We performed structural magnetic resonance imaging of the brain in 40 healthy adult participants who reported different degrees and patterns of religiosity on a survey. We identified four Principal Components of religiosity by Factor Analysis of the survey items and associated them with regional cortical volumes measured by voxel-based morphometry. Experiencing an intimate relationship with God and engaging in religious behavior was associated with increased volume of R middle temporal cortex, BA 21. Experiencing fear of God was associated with decreased volume of L precuneus and L orbitofrontal cortex BA 11. A cluster of traits related with pragmatism and doubting God’s existence was associated with increased volume of the R precuneus. Variability in religiosity of upbringing was not associated with variability in cortical volume of any region. Therefore, key aspects of religiosity are associated with cortical volume differences. This conclusion complements our prior functional neuroimaging findings in elucidating the proximate causes of religion in the brain.
Obviously these sorts of studies need to be viewed skeptically, the intersection of religion & fMRI seems very biased toward a high level of “sexiness.” Nevertheless, there are dozens of books on the psychology of religion, and, we know that religiosity is moderately heritable, so at some point the cognitive neuroscientists need to get in on the game of normal human variation in religious orientation (as opposed to studies of mystical brain states which seem focused on outliers). Here’s the conclusion, which takes some sides in long festering arguments about the evolutionary origins of religion: