Posts tagged ‘psychology’

Intelligence Is in the Genes, but Where?

You can thank your parents for your smarts—or at least some of them. Psychologists have long known that intelligence, like most other traits, is partly genetic. But a new study led by psychological scientist Christopher Chabris of Union College reveals the surprising fact that most of the specific genes long thought to be linked to intelligence probably have no bearing on one’s IQ. And it may be some time before researchers can identify intelligence’s specific genetic roots.

Chabris and David Laibson, a Harvard economist, led an international team of researchers that analyzed a dozen genes using large data sets that included both intelligence testing and genetic data.

In nearly every case, the researchers found that intelligence could not be linked to the specific genes that were tested. The results are published online in Psychological Science, a journal of the Association for Psychological Science.

“In all of our tests we only found one gene that appeared to be associated with intelligence, and it was a very small effect. This does not mean intelligence does not have a genetic component. It means it’s a lot harder to find the particular genes, or the particular genetic variants, that influence the differences in intelligence,” said Chabris.

It’s important to remember that we aren’t flowers, that intelligence is immensely more complex than the color of petals. There isn’t an “intelligence gene,” but rather a bunch of genes that influence it both individually and in cooperation with others. In addition, we aren’t positive on how the nurture-vs-nature relationship works in either. 



A 61-Million-Person Political Experiment on Facebook

If you saw one of above two ads pop up on your Facebook page on November 2, 2010, you may have silently participated in an huge behavioral study. Researchers from UCSD worked with Facebook to decipher what kind of messages were more effective in changing people’s behavior. 

One group of people were shown a voting/polling place reminder with their Facebook friends’ pictures, and some were shown the same message without social connections. A third group saw nothing. By cross-referencing those names with actual voting data, a small but significant number of people were convinced to vote by viewing the reminder along with their friends’ pictures.

The 0.39 percent increase means that 238,000 extra votes were cast … quite enough to turn an election in a swing state. They don’t know how this may translate to other behaviors and ads, but it shows that on the scale of large social networks, the subtle boost we receive by seeing a message connected to our social circle can change behaviors in meaningful ways.

Want more? You won’t believe how big the effect was when they started to dig into how people acted when close friends were featured in their message. Check out more details, and some of the skepticism, at Not Exactly Rocket Science.

(image from the Nature paper describing the research, subscription req’d)

One of the most powerful things about large-scale social media is that even the smallest of influence changes (I mean, .39% is pretty small) can have huge effects. 

Not just for advertising purposes, but in cases like this where the difference could be the leader of the free world..that’s incredible stuff. 

In a continuation of this study, I’d like to see how reliable the answers are. Did they really vote, and were they more or less likely to lie if their friends were being shown.


All vertebrates’ eyes emerge from a single group of cells, called the eye field, located in the middle of the brain. The eye field cells evaginate to form two optic vesicles, which eventually give rise to two retinas, one on either side of the brain.

Eyes Emerge

Top image: In a ~5 somites embryo, eye field cells are stained red, and forebrain cells are outlined in green (upper left). A few hours later, in a ~10 somites embryo, the eye field (green) separates into two optic vesicles. At the same embryonic stage, the dorsal telencephalon, which sits atop the evaginating eyes, is labeled blue (bottom left). In both of these images, a midline positioned cross outlines the apical surface of the optic vesicles and the ventricular space. The animation follows the development of this same surface as the eyes emerge from the brain.

Sunrise in the Eye

Bottom image: Once the basic shape of the eye is specified, cells within the optic cup differentiate, populating the retina with neurons that sense light and refine the visual information before it is transmitted to the brain. In fish and amphibia, retinal stem cells are maintained throughout the animal’s lifetime in a stem cell niche located adjacent to the lens (yellow). Here in situ hybridization of a zebrafish eye (from a ~ 3-day-old larva) reveals gene expression patterns that distinguish retinal stem cells (red) from the cells that are becoming neurons (purple). By comparing gene expression patterns within the retinal stem cell niche in normal and mutant eyes, we gain insight into how stem cells turn into neurons.

Eyes are not only amazingly complex, but are reducibly so!

Life for the winner is more glorious. It enters the next round of competition with already elevated testosterone levels, and this androgenic priming gives it an edge that increases its chances of winning yet again. Though this process an animal can be drawn into a positive-feedback loop, in which victory leads to raised testosterone levels which in turn leads to further victory.

The science of “the winner effect” and why success breeds more success. (via explore-blog)


Neuroscientist David Eagleman, author of the excellent Incognito: The Secret Lives of the Brain, explains the curious neurological wire-crossing of synesthesia. Complement with a synesthetic person’s first-hand account of the experience.

It seems today’s Tumblr theme is synesthesia. No complaints!

A neuronal kiss


A basket cell kissing a pyramidal cell
from the Blue Brain Project
-by Henry Markram

Researchers at UCLA have been studying the effect of music on human emotions. Specifically, what emotions dissonant (harsh, jarring, inharmonious) music invokes in us. They found that distortion and sharp changes in frequency generally made us feel more excited and carried negative emotions. It’s why rock music makes us so excited and the sound from the shower scene in Psycho is so scary. 

“This study helps explain why the distortion of rock ‘n’ roll gets people excited: It brings out the animal in us,” said Bryant.

As an explanation, the group believes that distorted music brings up the long-engraved fear and excitement rush of hearing an animal in distress. Most distress calls involve a sudden, unnatural expulsion of air through the voice box. The result is a distorted version of their normal sounds.