Behavior Genetics
razib | January 23, 2010In the wake of my post on selection and variation in dog skull shape, I thought it would be useful to point to this short paper, A canine chromosome 7 locus confers compulsive disorder susceptibility. Here's the conclusion:
The highly significant association of CCD with the CDH2 region on chromosome 7 is the first genetic locus identified for any animal compulsive disorder, and raises the intriguing possibility that CDH2 and other neuronal adhesion proteins are involved in human compulsive behaviors. A genetic association of cadherins with autism spectrum disorder, which often includes…
razib | January 19, 2010Heritability of the Specific Cognitive Ability of Face Perception:
What makes one person socially insightful but mathematically challenged, and another musically gifted yet devoid of a sense of direction? Individual differences in general cognitive ability are thought to be mediated by "generalist genes" that affect many cognitive abilities similarly without specific genetic influences on particular cognitive abilities. In contrast, we present here evidence for cognitive "specialist genes": monozygotic twins are more similar than dizygotic twins in the specific cognitive ability of face…
razib | December 1, 2009We May Be Born With an Urge to Help:
What is the essence of human nature? Flawed, say many theologians. Vicious and addicted to warfare, wrote Hobbes. Selfish and in need of considerable improvement, think many parents.
But biologists are beginning to form a generally sunnier view of humankind. Their conclusions are derived in part from testing very young children, and partly from comparing human children with those of chimpanzees, hoping that the differences will point to what is distinctively human.
The somewhat surprising answer at which some biologists have arrived is that babies are…
razib | August 17, 2009Below I repeated the contention that while schizophrenia is a genuine biologically rooted behavioral disease which can not be cured through will, many forms of addiction are not. That is why the genetics of schizophrenia are of such great interest, if the biological pathways of the pathology can be elucidated presumably a cure may be found. Unfortunately finding the genes is easier said than done, see Schizophrenia: The Mystery of the Missing Genes.
razib | July 23, 2009Earlier today I linked to a Jonah Leher post on food that hooks into the role that dopamine plays in our decision making. Dopamine looms in the neuroscience angle of Jonah's book How We Decide because the chemical's role in cognition is established. Dopamine related genes are often fingered in behavior genetic studies as the causal root of some observed psychological variation. So a new paper in Nature Neuroscience is in perfect position to stand astride the literal slush pile of this research, Prefrontal and striatal dopaminergic genes predict individual differences in exploration and…
razib | July 18, 2009Alex Tabarrok points me to a new paper on the effects of Toxoplasma gondii, Increased incidence of traffic accidents in Toxoplasma-infected military drivers and protective effect RhD molecule revealed by a large-scale prospective cohort study:
We confirmed, using for the first time a prospective cohort study design, increased risk of traffic accidents in Toxoplasma-infected subjects and demonstrated a strong protective effect of RhD positivity against the risk of traffic accidents posed by latent toxoplasmosis. Our results show that RhD-negative subjects with high titers of anti-Toxoplasma…
razib | June 29, 2009Arnold Kling highlights this section from a Scientific American article, The Science of Economic Bubbles and Busts:
But behavioral economics experiments routinely show that despite similar outcomes, people (and other primates) hate a loss more than they desire a gain, an evolutionary hand-me-down that encourages organisms to preserve food supplies or to weigh a situation carefully before risking encounters with predators.
One group that does not value perceived losses differently than gains are individuals with autism, a disorder characterized by problems with social interaction. When tested…
razib | June 17, 2009Common problem with loci presumed to have psychological or behavioral effects, Report on Gene for Depression Is Now Faulted:
The original finding, published in 2003, created a sensation among scientists and the public because it offered the first specific, plausible explanation of why some people bounce back after a stressful life event while others plunge into lasting despair.
The new report, by several of the most prominent researchers in the field, does not imply that interactions between genes and life experience are trivial; they are almost certainly fundamental, experts agree.
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Since…
razib | June 10, 2009The locus MAOA pops up every year or so in a study which attempts to correlate variation in these region with behavior. In particular, anti-social or pathological behavior. So another one is out, Monoamine oxidase A genotype is associated with gang membership and weapon use:
The low MAOA activity alleles conferred an increased risk of joining a gang and using a weapon in a fight for males but not for females. Moreover, among male gang members, those who used weapons in a fight were more likely to have a low MAOA activity allele when compared with male gang members who do not use weapons in a…
razib | May 13, 2009
When I found out a while back that Jonah Lehrer's next book was titled How We Decide, I knew I was going to check it out. It's no coincidence that I recently reviewed Predictably Irrational, I blog because I'm interested in reducing the human animal down its basic units of organization. Due to my disciplinary focus I generally touch upon behavior genetics or the inferences of human history one can glean from evolutionary genetics. History, psychology and economics are all domains which have piqued my interest. But I'll be honest and admit that I tend to avoid neuroscience because there's a…
razib | April 26, 2009The episode is titled "your brains & your genes." There's more emphasis on economics than you think.
razib | April 26, 2009Thankfully. Familial Resemblance of Borderline Personality Disorder Features: Genetic or Cultural Transmission?:
Borderline personality disorder is a severe personality disorder for which genetic research has been limited to family studies and classical twin studies. These studies indicate that genetic effects explain 35 to 45% of the variance in borderline personality disorder and borderline personality features. However, effects of non-additive (dominance) genetic factors, non-random mating and cultural transmission have generally not been explored. In the present study an extended twin-…
razib | April 20, 2009Bryan Caplan notes & argues:
If you take a closer look at BG research, though, you'll notice something interesting. Virtually every BG study partitions variance into three sources: genes, shared family environment, and non-shared environment. Typical estimates are something like 40-50% for genes, 0-10% for shared family environment, and 50% for non-shared environment.
And what exactly is non-shared environment? Everything other than genes and family environment!
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Nevertheless, I strongly suspect that if non-shared environment's contribution to behavioral variance were a lot smaller…
razib | April 9, 2009Jonah's interview of Judith Rich Harris is much recommended. Clearly related to my post on adoptive parents.
razib | April 9, 2009Via Dienekes, Differential parental investment in families with both adopted and genetic children:
Stepchildren are abused, neglected and murdered at higher rates than those who live with two genetically related parents. Daly and Wilson used kin selection theory to explain this finding and labeled the phenomenon "discriminative parental solicitude." I examined discriminative parental solicitude in American households composed of both genetic and unrelated adopted children. In these families, kin selection predicts parents should favor their genetic children over adoptees. Rather than looking…
razib | March 27, 2009A few days ago The New York Times had a blog post up which addressed the relationship between genes & environment in shaping our behavior & choices (see Genetic Future). One of the authors even posted a follow up comment where they evinced some surprise at the bile of the responses. I have to say that some people are naive; statistical sciences are a good reflection of the tenor of society. If you say a trait is 50% heritable, that is a statement of fact, but individuals will "spin it" however they want to based on their own outlook and the preferences of their target audience. Years…