Tuesday, March 30, 2010

Psychopaths’ brains seek rewards at all costs

Fascinating look at the brains of psychopaths. I know that in addictions the consequences are often completely ignored by the addict while in the acting out phase of the addiction cycle. I would strongly expect that this hyper-reactive dopamine reward system is in effect at some level with addicts too.

 

The brains of psychopaths appear to be wired to keep seeking a reward regardless of the consequences, according to new research.

“Psychopaths are often thought of as cold-blooded criminals who take what they want without thinking about consequences,” says the study’s lead author Joshua Buckholtz, a graduate student in psychology at Vanderbilt University.

“We found that a hyper-reactive dopamine reward system may be the foundation for some of the most problematic behaviors associated with psychopathy, such as violent crime, recidivism, and substance abuse.”

The results were published in Nature Neuroscience.

Previous research on psychopathy has focused on what these individuals lack—fear, empathy, and interpersonal skills. The new research, however, examines what they have in abundance—impulsivity, heightened attraction to rewards, and risk taking. Importantly, it is these latter traits that are most closely linked with the violent and criminal aspects of psychopathy.

“There has been a long tradition of research on psychopathy that has focused on the lack of sensitivity to punishment and a lack of fear, but those traits are not particularly good predictors of violence or criminal behavior,” says study coauthor David Zald, associate professor of psychology and of psychiatry. “Our data is suggesting that something might be happening on the other side of things. These individuals appear to have such a strong draw to reward—to the carrot—that it overwhelms the sense of risk or concern about the stick.”

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Monday, March 29, 2010

Are belly bacteria making us overeat?

Recent research suggesting that intestinal bacteria may actually change the host person's appetite and insulin resistance.

I'm curious what effect fasting and/or cleanse diets have on these bacteria colonies, and if foods like yogurt and other 'good bacteria' foods can have significant positive effect.

 

Intestinal bacteria also may play a role in human obesity and metabolic disease.

A new study shows that increased appetite and insulin resistance can be transferred from one mouse to another via intestinal bacteria.

Previous research has shown that intestinal bacterial populations differ between obese and lean humans.

“It has been assumed that the obesity epidemic in the developed world is driven by an increasingly sedentary lifestyle and the abundance of low-cost, high-calorie foods,” says senior author Andrew Gewirtz, associate professor of pathology and laboratory medicine at Emory University School of Medicine.

“However, our results suggest that excess caloric consumption is not only a result of undisciplined eating but that intestinal bacteria contribute to changes in appetite and metabolism.”

The study is published online in Science magazine.

Emory faculty member Matam Vijay Kumar has been studying mice with an altered immune system that were engineered to lack Toll-like receptor 5 (TLR5), a gene that helps cells sense the presence of bacteria.

TLR5 recognizes flagellin, the main component of the apparatus (flagella) that many bacteria use to propel themselves.

The TLR5-deficient mice were about 20 percent heavier than regular mice and had elevated triglycerides, cholesterol, and blood pressure, and mildly elevated blood sugar and increased production of insulin.

TLR5-deficient mice consumed about 10 percent more food than their regular relatives. When their food was restricted they lost weight but still had a decreased response to insulin (i.e. insulin resistance).

When fed a high-fat diet, TLR5-deficient mice gained more weight than regular mice and, moreover, developed full-blown diabetes and fatty liver disease.

In short, TLR5-deficient mice exhibit “metabolic syndrome,” a cluster of disorders that in humans increases the risk of developing heart disease and diabetes.

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Sunday, March 28, 2010

Selecting Talent: The Upshot from 85 Years of Research - Bob Sutton

Great article by Bob Sutton on hiring.

Most remarkable to me is how unpredictable on-the-job performance can be using:

  • unstructured interviews (most common in my experience),
  • reference checks (!), and
  • job experience (!!)

 

 

The upshot of this research is that work sample tests (e.g., seeing if people can actually do key elements of a job -- if a secretary can type or a programmer can write code ), general mental ability (IQ and related tests), and structured interviews had the highest validity of all methods examined (Arun, thanks for the corrections). As Arun also suggests, Schmidt and Hunter point out that three combinations of methods that were the most powerful predictors of job performance were GMA plus a work sample test (in other words, hiring someone smart and seeing if they could do the work),  GMA plus an integrity test, and GMA plus a structured interview (but note that unstructured interviews, the way they are usually done, are weaker).

Note that this information about combinations is probably more important than the pure rank ordering, as it shows what blend of methods works best, but here is also the rank order of the 19 predictors examined, rank ordered by the validity coefficient, an indicator of how strongly the individual method is linked to performance:

1. Work sample tests (.54)

2. GMA tests ..."General mental ability" (.51)

3. Employment interviews -- structured (.51) 

4. Peer ratings (.49)

5. Job knowledge tests (.48) Test to assess how much employees know about specific aspects of the job

6. T & E behavioral consistency method (.45) "Based on the principle that past behavior is the best predictor of future behavior. In practice, the method involves describing previous accomplishments gained through work, training, or other experience (e.g., school, community service, hobbies) and matching those accomplishments to the competencies required by the job. a method were past achievements that are thought to be important to behavior on the job are weighted and score

7. Job tryout procedure (.44) Where employees go through a trial period of doing the entire job.

8. Integrity tests (.41)  Designed to assess honesty ... I don't like them but they do appear to work

9. Employment interviews -- unstructured (.38)

10. Assessment centers (.37)

11. Biographical data measures(.35)

12. Conscientiousness tests (.31)  Essentially do people follow through on their promises, do what they say, and work doggedly and reliably to finish their work.

13. Reference checks (.26)

14. Job experience --years (.18)

15. T & E point method (.11)

16. Years of education (.10)

17. Interests (.10)

18. Graphology (.02) e.g., handwriting analysis.

19. Age (-01)

Certainly, this rank-ordering does not apply in every setting.  It is also important to recall that there is a lot of controversy about IQ, with many researchers now arguing that it is more malleable than previously thought. But I find it interesting to see what doesn't work very well -- years of education and age in particular. And note that unstructured interviews, although of some value, are not an especially powerful method, despite their widespread use. Interviews are strange in that people have excessive confidence in them, especially in their own abilities to pick winners and losers -- when in fact the real explanation is that most of us have poor and extremely self-serving memories.

Original Article: bobsutton.typepad.com

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Thursday, March 18, 2010

Hg Init: a Mercurial tutorial by Joel Spolsky

Hg Init: a Mercurial tutorial
Mercurial is a modern, open source, distributed version control system, and a compelling upgrade from older systems like Subversion. In this user-friendly, six-part tutorial, Joel Spolsky teaches you the key concepts.

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Wednesday, March 17, 2010

Liberals and Markets, Arnold Kling

Arnold Kling takes an interesting topic and dissects it well.

Are Libertarians simply Liberals who like markets?

I've considered myself a Libertarian in many political views for a long time, and have been noticing an increasing 'leftward' slide in my general political views, except for a couple hot-button areas.

Interesting:

 

To me, government is a mechanism that diffuses and dilutes accountability. If government does something wrong, does a bureaucrat get fired? Does an agency go out of business? Do legislators suffer financial losses?

If I shop for a coat, the store is accountable to me. If government decides on a policy, my affect on that policy is at best very indirect. Will my vote be determined by that policy, or by my feelings about the elected officials based on other factors? Even if I vote on the basis of a single policy, will others vote the same way? Will the elected officials understand what the voters want? etc.

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Saturday, March 13, 2010

What Truly “Wealthy” People Know about Money

This great article that I found via Seth Godin summarizes what I've been thinking and trying to actually do as far as generating value lately.

 

Look at the thing of value as what’s underneath the money.  If you want to generate more income, then think of how you can generate more value, not more money.  Also recognize that both value and wealth come in more forms than just money.  You can be financially wealthy but be bankrupt in true friendships, peer respect or health.

This observation is universal; applicable to anyone, anywhere in any business or organization.   It applies to the artist business, the management company and the United States Government.

In equation form it looks like this:

Wealth = Value Provided by Y *  Number of Entities that Directly Value Y

(Where Y is the product, employee or subject generating wealth).

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Monday, March 8, 2010

Attracting Talent, via Eric Lippert

Interesting summary of feedback by Eric Lippert, who was asking about factors that make a job description attractive (or not) to potential employees.

Factors that make a job posting attractive are:

  • Required skills
    • relevant, focused, sensible
    • emphasis on ability to learn
  • Format and style
    • well-written, self-aware, humble, enthusiastic
  • Personality and culture
    • good work-life balance
    • corporate culture and values clearly expressed
    • evidence of programming methodologies, such as “Agile Programming”
    • opportunity to work with famous industry leaders or on famous products
  • The job itself
    • described in detail: specific team, specific product, specific job
    • telecommuting possible
    • work is beneficial to industry and society
    • work has large scope -- “change the world”
    • work is challenging
    • product is innovative
    • tools/languages to be used are described and are current and familiar
    • good pay
    • autonomy to choose own tools, architectures, methodologies
    • details of the team stated – team size, for example
    • more than just typing in code – opportunities for UI design, DB design, troubleshooting user problems, and so on
via blogs.msdn.com

I highly recommend following the link and reading the whole article if you in any way participate in hiring, and/or drafting job requirements.

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Saturday, March 6, 2010

“It turns out” « jsomers.net

“It turns out” became a favorite phrase of mine sometime in mid 2006, which, it turns out, was just about the time that I first started tearing through Paul Graham essays. Coincidence?

I think not. It’s not that pg is a particularly heavy user of the phrase—I counted just 46 unique instances in a simple search of his site—but that he knows how to use it. He works it, gets mileage out of it, in a way that other writers don’t.

That probably sounds like a compliment. But it turns out that “it turns out” does the sort of work, for a writer, that a writer should be doing himself. So to say that someone uses the phrase particularly well is really just an underhanded way of saying that they’re particularly good at being lazy.

Let me explain what I mean.

Suppose that I ...(continued after the link)...

This is an engaging post about the use (and abuse) of a rhetorical phrase that gives the user immense influence, without actually needing the weight of facts to substantiate it.

I've always found this phrase quite compelling, and reading this post was quite entertaining. (HT Ben Casnocha)

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Thursday, March 4, 2010

Classy, Affordable, and Attractive Closet Space Solutions

 

Dave and Andrea Walker over at INeedClosetSpace.com have been doing some great work in organization and space management of garages and closets...

 

I especially like the classy and organized look of a few of their solutions:

 

John Louis Home

 

They are located in Battle Ground, just north of Vancouver, WA

 

I highly recommend them!

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