We could flip a coin to decide which ref to believe. But this merely gives us a decision performance which is the average of the decision performance of each individual ref. So this is no good.

We could figure out which ref is better and then always believe that ref whenever the two refs disagree. But in that case the second ref isn’t contributing anything, so we may as well just have one ref.

However, if the two refs have some estimate of their uncertainty, then we can do better. If d1 represents where ref one thinks the ball landed, and d2 represents what ref 2 thinks, and if o1 and o2 represent each ref’s report of the standard deviation of their own estimate, then the optimal way to combine both refs’ guesses into a final guess is

(d1/o1^2 + d2/o2^2) / (1/o1^2 + 1/o2^2)

which gives better performance than either ref, individually. Since we only care about whether the ball went over the line, if the line is at d=0, then this rule simplifies to testing if

d1/(o1^2) + d2/(o2^2) > 0

Is that what humans do? No. Apparently, when put together in pairs and given the chance to communicate, humans communicate both their guesses and their uncertainties, and effectively use the following formula to make a cooperative guess:

d1/o1 + d2/o2 > 0

This rule provides better performance than individual decision-making provided the difference between o1 and o2 (the uncertainties of the refs) is less than 40%. If it is more than that, this rule is worse than just having the more reliable ref make all the decisions.

Why do humans use d1/o1 + d2/o2 instead of the optimal formula, d1/o1^2 + d2/o2^2? One hypothesis is that the former is unit-free, whereas the latter requires both refs to communicate with each other in terms of (matching) spatial units.

summary:

Marc O. Ernst. Decisions Made Better (27 August 2010)
Science 329 (5995), 1022.

article:

Bahador Bahrami, Karsten Olsen, Peter E. Latham, Andreas Roepstorff, Geraint Rees, and Chris D. Frith. Optimally Interacting Minds (27 August 2010)
Science 329 (5995), 1081.

In her book Delusions of Gender (which I have not read though am intrigued to do so), cognitive neuroscientist Cordelia Fine places several modern studies of early differences in brain anatomy/function into a long line of sexist explanations for supposed differences in male and female behaviors.

The basic argument is that there has been no convincing connection made between any measured structural differences (which she argues might not exist) to behavioral differences. Just another case of correlation (maybe) and not causation.

Here’s a description of study that you might already be familiar with and Fine’s take on it:

Dr. Baron-Cohen’s lab conducted research on infants who averaged a day and a half old, before any unconscious parental gender priming. Jennifer Connellan, one of Dr. Baron-Cohen’s graduate students, who conducted the study, showed mobiles and then her own face to the infants. The results showed that among the newborns the boys tended to look longer at mobiles, the girls at faces.

Dr. Fine dismantles the study, citing, among other design flaws, the fact that Ms. Connellan knew the sex of some of the babies. Because it was her face they were looking at and she was holding up the mobile, Dr. Fine says, she may have “inadvertently moved the mobile more when she held it up for boys, or looked more directly, or with wider eyes, for the girls.”

Although I am unsure about the scientific merits, it is refreshing to see a new viewpoint in this debate. It provides some food for thought on this interesting topic:

Summarizing the research, she writes, “Nonexistent sex differences in language lateralization, mediated by nonexistent sex differences in corpus callosum structure, are widely believed to explain nonexistent sex differences in language skills.”

What all this adds up to, she says, is neurosexism. It’s all in the brain.

After the jump some more from Junger and a nice talk from Robert Sapolsky about similar behaviors in chimps.

Another example from soldiers in Afghanistan is the “blood-in, blood-out” ritual for increasing group cohesiveness and testing individual sacrifice for the group, as Junger describes near the end of this Daily Show clip:

All of these explanations and rituals reminded me of Robert Sapolsky’s and Frans de Waal’s observations of similar behavior that is reported in baboon/chimp groups.

In the clip below (from Stanford’s Class Day 2009 speech), Sapolsky describes several “uniquely human” behaviors (or at least ones that had been thought to be “uniquely human”) which really are shared by these close relatives. Starting around 12:20 (the clip below will auto-start there), he talks about aggression and the organized group killing done by “border patrols”. The entire talk by Sapolsky (~35 mins) is worth watching too!

Paul Bloom talks about research on the morality of small children, and ways in which their morality is similar to and different from adults. Concise descriptions of supporting experiments is given throughout.

Basically, babies prefer nice people over mean people, but prefer people who punish mean people over people who reward mean people. But babies are not impartial; for example, they give favorable treatment to other babies who are wearing the same tee-shirt as themselves.

Also has some content about the cognition of babies in general. Experiments show that, at various young ages, “..babies think of objects largely as adults do, as connected masses that move as units, that are solid and subject to gravity and that move in continuous paths through space and time,” and “…expect people to move rationally in accordance with their beliefs and desires…”, and “…know that other people can have false beliefs”.

Watch it online at the TED website.

I’m a fan of it because it is an open-access journal featuring a “tiered system” and more.  From their website:

The Frontiers Journal Series is not just another journal. It is a new approach to scientific publishing. As service to scientists, it is driven by researchers for researchers but it also serves the interests of the general public. Frontiers disseminates research in a tiered system that begins with original articles submitted to Specialty Journals. It evaluates research truly democratically and objectively based on the reading activity of the scientific communities and the public. And it drives the most outstanding and relevant research up to the next tier journals, the Field Journals.

I’m a big fan of the variety of specialty journals they have:

• Aging Neuroscience
• Behavioral Neuroscience
• Cellular Neuroscience
• Computational Neuroscience
• Enteric Neuroscience
• Evolutionary Neuroscience
• Human Neuroscience
• Integrative Neuroscience
• Molecular Neuroscience
• Neural Circuits
• Neuroanatomy
• Neuroenergetics
• Neuroengineering
• Neurogenesis
• Neurogenomics
• Neuroinformatics
• Neuromethods
• Neuropharamacology
• Neuroprosthetics
• Neurorobotics
• Synaptic Neuroscience
• Systems Neuroscience

Just last night, I watched the tense but amazing film The Hurt Locker (don’t let the name disuade you, see the phenomenal Metacritic rating), which is about a bomb disposal squad during the recent Iraq War. There is one particularly stirring scene with a suicide bomber who claims that he was forced to wear a vest with explosives and doesn’t want to go through with it. The difficulty in the limited time before the bomb explosion revolves around whether to actually trust the man and the challenge of trusting someone when neither party speaks the other’s language. You can certainly at least understand (putting aside the ethics of war itself) why governments are interested in detecting nonverbal trust cues.

Details about the IARPA call for proposals are after the jump.

IARPA is soliciting submissions on the following areas aimed at
addressing the challenges of defining, understanding, and ultimately
detecting valid, reliable signatures of trust in humans:

1.) Different kinds of trust and what, if any, kinds of
neurophysiological signals might be associated with them. IARPA seeks
to understand the different manifestations that trust may take (i.e.
swift trust, conditional trust, unconditional trust, etc.) as well as
the different neurophysiological processes associated with one or more
of these kinds of trust.

2.) New models of neural systems and patterns of neural activation
related to different kinds of trust and associated neurophysiological
signatures of those activation patterns. IARPA seeks to understand the
degree to which the neural-bases of trust(s) may assist in detecting
peripheral signals of trust and trustworthiness under different
conditions.

3.) Potentially novel preconscious signals or combinations of signals
- neural, endocrine, physiological, behavioral, etc. – that may be
indicative of trust or trustworthiness among people in different
contexts. IARPA seeks to elucidate signals and neurobiological
processes that humans may use for assessing trust, but which are not
yet – or are currently poorly – understood.

4.) New sensor technologies or combinations of technologies that can
assist in detecting subtle but valid and reliable changes in
neurophysiological states that may be indicative of trust among
humans. IARPA seeks to explore the feasibility of using technology to
amplify systems that humans have evolved to preconsciously assess
trust in others.

5.) Novel, ecologically-valid, but ethical “trust-based” protocols
designed to assess the validity and reliability of potential trust
signals among two or more humans. IARPA seeks to develop new, more
sophisticated processes for understanding near real-time human
preconscious assessment of trust in near real-world circumstances.

It is nice how YouTube can be both educational and entertaining!

Case No. 158

An attractive, amiable boy from a working-class background, you struck the study staff as happy, stable, and sociable. “My general impression is that this boy will be normal and well-adjusted—rather dynamic and positive,” the psychiatrist reported.

After college, you got an advanced degree and began to climb the rungs in your profession. You married a terrific girl, and you two played piano together for fun. You eventually had five kids. Asked about your work in education, you said, “What I am doing is not work; it is fun. I know what real work is like.” Asked at age 25 whether you had “any personal problems or emotional conflicts (including sexual),” you answered, “No … As Plato or some of your psychiatrists might say, I am at present just ‘riding the wave.’” You come across in your files as smart, sensible, and hard-working. “This man has always kept a pleasant face turned toward the world,” Dr. Heath noted after a visit from you in 1949. From your questionnaire that year, he got “a hint … that everything has not been satisfactory” at your job. But you had no complaints. After interviewing you at your 25th reunion, Dr. Vaillant described you as a “solid guy.”

Two years later, at 49, you were running a major institution. The strain showed immediately. Asked for a brief job description, you wrote: “RESPONSIBLE (BLAMED) FOR EVERYTHING.” You added, “No matter what I do … I am wrong … We are just ducks in a shooting gallery. Any duck will do.” On top of your job troubles, your mother had a stroke, and your wife developed cancer. Three years after you started the job, you resigned before you could be fired. You were 52, and you never worked again. (You kept afloat with income from stock in a company you’d done work for, and a pension.)

Seven years later, Dr. Vaillant spoke with you: “He continued to obsess … about his resignation,” he wrote. Four years later, you returned to the subject “in an obsessional way.” Four years later still: “It seemed as if all time had stopped” for you when you resigned. “At times I wondered if there was anybody home,” Dr. Vaillant wrote. Your first wife had died, and you treated your second wife “like a familiar old shoe,” he said.

But you called yourself happy. When you were 74, the questionnaire asked: “Have you ever felt so down in the dumps that nothing could cheer you up?” and gave the options “All of the time, some of the time, none of the time.” You circled “None of the time.” “Have you felt calm and peaceful?” You circled “All of the time.” Two years later, the study asked: “Many people hope to become wiser as they grow older. Would you give an example of a bit of wisdom you acquired and how you came by it?” You wrote that, after having polio and diphtheria in childhood, “I never gave up hope that I could compete again. Never expect you will fail. Don’t cry, if you do.”

What fascinates me is the absolute novelty of this kind of data. Normally, when someone relates their “life story,” we willingly participate in something of a shared lie. Both listener and story-teller know that the “life story” is being told in hindsight: Memory is not perfect and humans sometimes (often, perhaps) add meaning and create unifying themes in stories where they may be none. We emphasize the good parts and try to forget the not-so-good parts. In a sense, history recounted is never truly veridical but instead tainted with everything that happened after. Which is precisely why the availability of an objective history than spans an entire lifetime (or, as objective as possible) of both a qualitative (interview) and quantitative (medical) nature is so novel.

As you might expect, the data is confusing and hard conclusions are not easy to come by. There are however some tangible factors that seemed to correlate/predict success in life, which I’ve included after the jump. What predicts success in life? What predicts failure?

What allows people to work, and love, as they grow old? By the time the Grant Study men had entered retirement, Vaillant, who had then been following them for a quarter century, had identified seven major factors that predict healthy aging, both physically and psychologically.

Employing mature adaptations was one. The others were education, stable marriage, not smoking, not abusing alcohol, some exercise, and healthy weight. Of the 106 Harvard men who had five or six of these factors in their favor at age 50, half ended up at 80 as what Vaillant called “happy-well” and only 7.5 percent as “sad-sick.” Meanwhile, of the men who had three or fewer of the health factors at age 50, none ended up “happy-well” at 80. Even if they had been in adequate physical shape at 50, the men who had three or fewer protective factors were three times as likely to be dead at 80 as those with four or more factors.

What factors don’t matter? Vaillant identified some surprises. Cholesterol levels at age 50 have nothing to do with health in old age. While social ease correlates highly with good psychosocial adjustment in college and early adulthood, its significance diminishes over time. The predictive importance of childhood temperament also diminishes over time: shy, anxious kids tend to do poorly in young adulthood, but by age 70, are just as likely as the outgoing kids to be “happy-well.” Vaillant sums up: “If you follow lives long enough, the risk factors for healthy life adjustment change. There is an age to watch your cholesterol and an age to ignore it.”

The study has yielded some additional subtle surprises. Regular exercise in college predicted late-life mental health better than it did physical health. And depression turned out to be a major drain on physical health: of the men who were diagnosed with depression by age 50, more than 70 percent had died or were chronically ill by 63. More broadly, pessimists seemed to suffer physically in comparison with optimists, perhaps because they’re less likely to connect with others or care for themselves.

There is also a nice video of the George Valliant (who has run the study for the last 40 years) along with the article.