Why did this tactic work? We frequently make decisions based on inferences from the behavior of others. Choosing between options is a time-consuming and difficult task. Why not rely on the behavior of others? Even if we took the time and effort to weigh our options, we might still have only a single “decision” information (technical term: signal). That is, our weighing and adding might result in say, a Buy decision. However, from the actions of others we gain other ‘pieces of information’. We infer that they have made similar weighing and adding and have thus come to their own conclusions or decisions as well. In this case, the few people that you have polled, say 8 out of 10 people, decided on a Sell decision. How sure are you that your initial Buy decision was correct? How likely are you to ignore the decision trend that you have observed and go with the decision that you initially decided on?

“When people are free to do as they please, they usually imitate each other.” – Eric Hoffer (1955)

In the example arlier, you are the 11th person to make the decision and the informational cascade is well on its way. But what if you were only the 3rd person to make the decision, what would your role be in the formation of the cascade? Let say Person 1, Alice, made the decision to Accept. You would have inferred that Alice received information that was good (given that she had no predecessor’s behavior to observe). The person 2, Brenda, then makes the decision to Accept as well. Now Brenda might have received a good signal or she might have received a bad one and decided to go with a toss of the coin. Chances are, you will go with the inference that Brenda received a good signal as it is of a higher probability. Now it’s your turn, if you get a good signal as well, hurrah! your decision has been made. But what if you received a bad signal? It is still more optimum for you to go with an Accept decision, ignoring your private signal. In doing so, you have started the informational cascade. Even if Brenda’s toss of a coin resulted in a Reject, the informational cascade would only be delayed but not stumped. Thus, showing one important feature of a cascade — it is usually based on very little information.

Of course, if you possess some special knowledge or information, you are likely to be more confident of your initial decision and more likely to reject the influence of the ‘informational cascade’ and go with your personal decision. In this case, if there are enough of you, the cascade might be reversed in the opposite direction. Thus, cascades while powerful are very fragile and susceptible to shocks. The arrival of better informed individuals (like yourself) or the release of new information might shift the cascade in the opposite direction.

[To read more about informational cascades, see Sushil Bikhchandani, David Hirshleifer & Ivo Welch (1998)]

All hurricanes start off as tropical storms and only officially become hurricanes when they reach wind speeds of 74 miles per hour. They are named while they are still tropical storms and they retain their name even after they’ve matured into a hurricane. Think of tropical storms as babies and hurricanes as the angsty havoc-wrecking teenagers.. unless they decide to become pop stars, they usually retain their birth names.

The convention of giving hurricanes female names started in the 19th century with an Australian meteorologist. The practice only caught on in the World War II, where the easily remembered names gained popularity and helped increase public awareness of the hurricanes. Previously, hurricanes were either given technical names indicating the latitude/longitude or were named after saints in the Catholic liturgical calendar. In 1978, Atlantic meteorologists began alternating between male* and female names for the tropical storms and the practice has stuck ever since.

A list of 21 male and female names are used each year, and the names are arranged alphabetically. Hence, the first tropical storm next year would be called Alex and the second would be Bonnie. There are 6 lists in total and the lists are rotated every 6 years. Names for storms are sometimes reused with a few exceptions — names that conjure too much pain and horror are retired in order to be sensitive towards the victims.

*Thanks to missconstrue for pointing out that Atlantic tropical storms and hurricanes have both male and female names.

[Read more about hurricane names in Geology.com and in FEMA]

In particular:

• Fibre: Microbes in our body are fed by our dietry fibre intake and thus reducing the amount of calories by as much as 25%.
• Protein: Energy is needed to break down protein into amino acids, leading to a reduction in 20%.
• Texture: The difference between eating something soft and something hard directly impacts the amount of chewing required and is thus also impacts the amount of calories absorbed. Researchers fed lab rats either hard or soft pellets and found that those on the hard-diet were slimmer and had less fat around the mid-section. Results from human studies concurred with this result, with the women who ate the hardest food (defined as hardest to chew) having the slimmest waists.
• Simple vs Complex Carbs: While refined carbohydrates (e.g. sugar, flour) can be completed digested by the body, other coarser carbohydrates (e.g. oatmeal) may only be partially digested (about 70%). Oprah knew this all along when she encouraged her viewers to skip white carbs and stick to the browns.
• Cooked vs Raw: Cooking helps food become more easily digested and thus increases the amount of calories that can be extracted. Heat from cooking changes amylopectin in starch into more easily digestable amylose. In proteins, heats unfolds the structure of protein molecules for easier conversion into the amino acids required by the body. Cooking thus, can reduce the cost of digestion by as much as 12.7%.

[Read more about The Calorie Delusion in New Scientist, 15 July 2009]

Researchers in Germany have recently showed that certain chemicals in our sweat signal stress and when we smell someone else’s ‘stress’ sweat, it triggers the same feeling as well. The researchers placed absorbent pads in the armpits of students before an exam and also while they exercised. They then gave these two different kinds of sweat pads to participants and found that the participant’s brain areas related to social and emotional signals as well as empathy lighted up when exposed to the stress pads but not the exercise ones. The participants were not able to differentiate between the two different kinds of sweat, indicating that the processing of this information bypasses consciousness. The article did not say, but I wonder if participants who were exposed to the stress pads experienced an increase in cortisol levels as well?

[Read more about the smell of fear in New Scientist, 4 July 2009 and in Science Daily, 8 March 2009.]

[Read more about other world-changing inventions that didn't in Cracked.com]

2) Aberrant - deviating from the norm. His aberrant personality makes finding a mate an impossibility!

3) Alacrity – eager and enthusiastic willingness. He greeted us with such alacrity!

4) Anomaly (was my fav word of the week several weeks ago!) – deviation from the normal order, form, or rule; abnormality. What makes you sure that this is not just a statistical anomaly?

5) Approbation – an expression of approval or praise. My father gave me his prized watch as a symbol of his approbation.

6) Arduous (ditto!) – strenuous; taxing; requiring significant effort. He was disheartened by the arduous path he knew lay ahead.

7) Assuage (ditto!) – to ease or lessen; to appease or pacify. She hoped that giving alms to the poor would assuage her guilt.

[Note: I decided that I'm gonna skip the words that I know.. save time!]

8) Axiomatic – taken as given; possessing self-evident truth; based on or involving a set of axioms or system of axioms. It is axiomatic that what follows the night is always dawn.

9) Chicanery – trickery or subterfuge. Some chicanery is required to get out of this difficult situation.

10) Disabuse – to undecieve; to set right; to free from error, fallacy or misconception. You must be disabused of your belief that there is a god!

Experts predict that the land affected by the nuclear disaster will not be suited for human habitation nor crop growing for hundreds of years until the radioactive isotopes have sufficiently decayed. Also, thousands of people living further away have been found to be consuming food with dangerously high levels of radioactivity. Thus, there is an urgent need for a way to remove the radioactive material from the area or at least reduce its continued damage.

Now, some scientists propose growing biofuels, such as sugar beet, in the area “to suck up” the radioactive material from the ground. These biofuels will then be sold to state agencies which will then make them available across Europe. The biofuels will be processed and distilled for ethanol, leaving behind radioactive ash to be disposed of at nuclear waste treatment plants. If implemented, the decontamination of the land can be expected within 40 to 50 years, a breath away compared to hundreds of years needed for the radioactive material to decay naturally. While officials are upbeat about the prospects of the biofuels project, the lack of such treatment plants in Belarus poses some problems. Nonetheless, the government at Belarus has vowed to resolve this issue and I’m sure a suitable treatment plant can be built in the area for the implementation of this project.

[Read more about how biofuels can save Chernobyl in New Scientist, 27 June 2009 and in Clean Technica, 24 September 2008]

Jim Kakalios, expert in swatting (of the superhero variety) was called in to explain Obama’s deadly fly thwarting skills:

Obama smacked the fly by moving his arm downward in a throwing motion, an action humans honed through evolution, [...] and strategically trapped it above his left arm. That meant the insect’s only possible escape route was flying up—straight into a descending hand.

[Read more about Obama's fly swatting incident in Discover magazine, 18 June 2009]

Psychologist have coined the term ‘emotional contagion’ to describe how emotions can spread from one person to another without them being consciously aware. The world is full of mood triggers — an encounter with a chirpy waitress will lift you mood a little just like how seeing a smiling face will cause our facial muscles to mimic the smile ever so slightly.

Marital researchers took such emotional mimicry one step further and filmed couples having arguments. Levenson and Ruef (1992) tracked the physiological measures (cardiac, vascular, electrodermal, and somatic muscular) of the couples quarrelling as well as of observers watching the recording of the argument. They found that not only do the observers’ physiological measures follow that of the couple that they are observing, but that the more closely matched their physiological measures are, the more accurate their guess of the observed feelings. This effect is especially pronounced for negative emotions such as anger. Thus, forming the biological basis for empathy.

[Read more about emotional contagion and how humans relate to one another in 'Social Intelligence' by Daniel Coleman]

1) It tends to infect the relatively young — the median age in California is 27.5 years and more than 60% of all infected cases are younger than 25 years. This might be good news for older folk as their prior flu infections (some of which may be similar to the swine flu strain) may have strengthened their immunity to the current strain.

2) Deaths from H1N1 are much less than those from regular seasonal flu – while the regular seasonal flu has a death toll in the range of tens of thousands a year, the current deaths from H1N1 are no more than 200 (health officials around the world are now being more prudent about releasing death toll figures so the exact figure is unknown).

3) The economy as the collateral damage — As if the global economy is not in a bad enough shape, a 2008 World Bank report predicts that a severe pandemic will reduce the world GDP by 4.8%. Even if the pandemic ends up relatively mild, trade disruptions and travel restrictions might still inflict much pain on the economy.

At the end of the day, the conclusion should not be to “laugh in the face of swine flu” (to quote my Professor), but to take adequate precautions and practice good hygiene and not let the fear of infection affect us more than it should.

[Read more about swine flu in Time magazine and in CDC]