One of the pitfalls about talking about genetics, especially human genetics, is that the public wants a specific gene for a specific trait. Ergo, the “God gene” or the “language gene.” In some cases science has been able to pull a rabbit out of the hat, and offer up a gene for a trait. But in most of those instances these are going to be single gene recessive diseases. Not exactly what the doctor ordered. In other cases the association seems trivial. For example, wet or dry earwax?* What people are truly interested in are the genetic basis of complex traits, such as intelligence, personality, and height. Unfortunately complex traits often have a complex genetic basis. A trait such as height, which is highly heritable (i.e., most of the variation in the population is due to variation in genes), turns out to be subject to the control of innumerable genes, each of which has a small impact on the value of the final trait. Then there is the possibility that the heritability is tied up to interaction effects across genes.
Over at Scientific American Christie Wilcox has a post up with the provocative title, People With Brown Eyes Appear More Trustworthy, But That’s Not The Whole Story, which reports on a new PLoS ONE paper, Trustworthy-Looking Face Meets Brown Eyes. Like Christie I would enjoy illustrating this post with my own trustworthy and youthful brown eyed visage, but I worry that my mien is a bit on the sly side! In any case, what of the paper? Wilcox reviews the salient points of the results. In short, the issue here is that brown eyed men seem to have more ‘trustworthy faces’ than blue eyed men. When the eyes were digitally manipulated it turned out that color had no influence on perception. Rather, it was the correlation between eye color and facial proportion which which was driving the initial association. Christie finishes:
Given the importance of trust in human interactions, from friendships to business partnerships or even romance, these findings pose some interesting evolutionary questions. Why would certain face shapes seem more dangerous? Why would blue-eyed face shapes persist, even when they are not deemed as trustworthy? Are our behaviors linked to our bodies in ways we have yet to understand? There are no easy answers. Face shape and other morphological traits are partially based in genetics, but also partially to environmental factors like hormone levels in the womb during development. In seeking to understand how we perceive trust, we can learn more about the interplay between physiology and behavior as well as our own evolutionary history.
If you aren’t too stuffed, ask! I plan to get my simultaneous review of The Signal and the Noise: Why So Many Predictions Fail-but Some Don’t and Uncontrolled: The Surprising Payoff of Trial-and-Error for Business, Politics, and Society up over the holiday weekend, but I’m going to be focused on other things besides the blog obviously. That being said, to be frank I don’t personally feel that the regular reader of this weblog would get much value from The Signal and the Noise (Nate Silver interviews Robin Hanson. I didn’t need to read his book to be aware of Robin Hanson’s ideas, he quite freely shares them to all curiosity seekers on the internet and in person). Uncontrolled adds more value in my opinion because experiments in social science are more difficult, and probably more genuinely ground-breaking (if less sexy), than statistical inference.
Jacques Barzun died last week. From Dawn to Decadence is one of those books which is useful not as much for its descriptive sweep of social history, but for the insights and counter-narratives which it may elicit. I am left in awe of the life of the mind which Barzun experienced in his time.
H/T Steve Sailer.
You know that Newsweek is ending its print edition. This was long in the coming. What I find interesting is that apparently its circulation peaked in 1991, at 3.3 million. It declined to 3.1 million in 2007, and literally cratered over the past 5 years to 1.5 million! Thinking back to my own past I remember my interest in Newsweek‘s cartoons, as well as the in-class discussion triggered by the latest issue of Time. There was a time when these were relevant publications. But that ended in 1995, with the rise of the internet. For years the weeklies still maintained the illusion of relevance, but I think they were living on borrowed time. People went through the motions because they always had. After all, the cover of Time was important, everyone knew it. Until no one did. The collapse in circulation is just a reflection of the fact that this emperor had long ago shed its clothes.
Last spring I made a bet with a friend that Mitt Romney would win. He gave me 5:1 odds, and I assumed a 40% chance that Romney would win. So I expected to lose, but if I won I’d win big. At this point I assume I’m out that money, because I’d put Romney’s chances at less than 40% (though I think people underweight uncertainty, so I believe there’s a lot of variation in this prediction). But now I’m hearing/reading that many Republicans are under the impression that the polls are skewed. If you believe that the polls are skewed would you be willing to bet money that the polls are skewed? Specifically, I want to wager that “unskewed polls” turn out to be further off the mark than the regular polls in reference to the final election results. I’m not 100% sure that the pollsters are correct, and I don’t know more than a superficial amount as to the weighting methodologies, but the track record of skew-skeptics is suspect enough that I think this is a way I can make money off people who I perceive to be suckers. Of course, the people who I perceive to be suckers think I’m the sucker, which is fair enough. Take my money! Please speak up in the comments if you want to make a bet. I’d want it to be public, and you have to put your real name out there. Also, I want to know if you’ll give me some odds, because I assume you are moderately confident in your assessment that the polls are skewed.
Just found out that Steve Sabol of NFL films passed away a few days ago. I don’t really watch spectator sports anymore, but I remember the important role that Sabol’s films played in my life leading up the week’s games, as you had to wait day by day. I’m no longer in middle school, but I still recall what it was like.