Thursday, October 22, 2009

Choosing Your Financial Path

Site of the day:

Oh man, this guy isn't joking:

Monday, October 19, 2009


Site of the day:

Nootropics, also referred to as smart drugs, memory enhancers, and cognitive enhancers, are drugs, supplements, nutraceuticals, and functional foods that are purported to improve mental functions such as cognition, memory, intelligence, motivation, attention, and concentration.[1][2] The word nootropic was coined in 1964 by the Romanian Dr. Corneliu E. Giurgea, derived from the Greek words noos, or "mind," and tropein meaning "to bend/turn". Nootropics are thought to work by altering the availability of the brain's supply of neurochemicals (neurotransmitters, enzymes, and hormones) by improving the brain's oxygen supply or by stimulating nerve growth. However the efficacy of nootropic substances in most cases has not been conclusively determined. This is complicated by the difficulty of defining and quantifying cognition and intelligence.

Availability and prevalence

At present, there are several drugs on the market that improve memory, concentration, planning, and reduce impulsive behavior. Many more are in different stages of development.[3] The most commonly used class of drug are the stimulants.[4]
These drugs are used primarily to treat people with cognitive difficulties: Alzheimer's disease, Parkinson's disease, ADHD. However, more widespread use is being recommended by some researchers. These drugs have a variety of human enhancement applications as well, and are marketed heavily on the World-Wide Web. Nevertheless, intense marketing may not correlate with efficacy; while scientific studies support some of the claimed benefits, it is worth noting that many of the claims attributed to most nootropics have not been formally tested.
In academia, modafinil has been used to increase productivity, although its long-term effects have not been assessed in healthy individuals.[3] Stimulants such as methylphenidate and atomoxetine are being used on college campuses, and by an increasingly younger group.[3] One survey found that 7% of students had used stimulants for a cognitive edge in the past year, and on some campuses the number is as high as 25%.[4]


The main concern with pharmaceutical drugs is adverse effects, and these concerns apply to cognitive-enhancing drugs as well. Cognitive enhancers are often taken for the long-term when little data is available.[3]
Dr. Corneliu E. Giurgea originally coined the word nootropics for brain-enhancing drugs with very few side-effects. Racetams are sometimes cited as an example of a nootropic with few effects and wide therapeutic window;[5] however, any substance ingested could produce harmful effects. An unapproved drug or dietary supplement does not have to have safety or efficacy approval before being sold.[6] (This mainly applies to the USA, but may not apply in the EU or elsewhere.)
Some dangers of nootropics include, but are not limited to:
-Downregulation of neurological activity upon stimulation, resulting in a permanent or temporary hypoactive system and/or addictive properties (applies to dopamine, choline, and many other neurotransmitter systems)
-Serotonin syndrome from serotonergic agents
-Excessive acetylcholine receptor activation - see acetylcholinesterase inhibitor
-Heart failure, such as that from stimulants or any substance which alters heart rate
-Organ failure such as liver failure and kidney failure


The term "drug" here is used as a legal designation. Although some of the effects of these substances may be similar to others, only those substances that have shown cognitive effects are included.

Nootropics and racetams

The word nootropic was coined upon discovery of the effects of piracetam, developed in the 1960s.[7] Although piracetam is the most commonly taken nootropic,[7] there are many relatives in the family that have different potencies and side-effects. Other common racetams include pramiracetam, oxiracetam, and aniracetam. There is no generally-accepted mechanism for racetams. In general, they show no affinity for the most important receptors, although modulation of most important central neurotransmitters, including acetylcholine and glutamate, have been reported.[8] Although aniracetam and nebracetam show affinity for muscarinic receptors, only nefiracetam shows it at the nanomolar range. Racetams have been called "pharmacologically safe" drugs.[5]
Other substances sometimes classified as nootropics include hydergine, vinpocetine, bifemelane, huperzine A (cholinergic activator below), and dimethylaminoethanol.[5]


Stimulants are often seen as smart drugs, but are actually just productivity enhancers. These typically improve concentration and a few areas of cognitive performance, but only while the drug is still in the blood. Some scientists recommend widespread use of stimulants such as methylphenidate and amphetamines by the general population to increase brain power.[4][9]

-Amphetamine (Adderall, Dexedrine) - adrenergic, dopaminergic
-Lisdexamfetamine (Vyvanse) - adrenergic, dopaminergic
-Methamphetamine (Desoxyn) - adrenergic, dopaminergic
-Methylphenidate (Ritalin) - adrenergic, dopaminergic


Eugeroics ("Wakefulness Enhancers") - unproven primary mechanisms but proven efficacy

Xanthines - reduces fatigue perception


Dopaminergics are substances that affect the neurotransmitter dopamine or the components of the nervous system that use dopamine. Attributable effects of dopamine are enhancement of attention, alertness, and antioxidant activity. Dopamine is the primary activity of stimulants like methylphenidate (Ritalin) or amphetamine. Dopaminergic nootropics include dopamine synthesis precursors, dopamine reuptake inhibitors, monoamine oxidase inhibitors, and other compounds:

Metabolic precursors - raise levels
-L-Phenylalanine - purported cognitive improvement
-L-Tyrosine - purported cognitive improvement

Reuptake inhibitors - stabilize/improve levels
-Amineptine - mild stimulant
-MAO-B inhibitors - prevent breakdown
-Selegiline - mild stimulant

-cocaine and the relatives - multiple mechanisms that amplify dopamine release
-amphetamine and relatives
-Yohimbe - purported dopaminergic activity

Memory enhancement

Memory can come from many different processes, but is dependent on the ability to store and recall information.


Cholinergics are substances that affect the neurotransmitter acetylcholine or the components of the nervous system that use acetylcholine. Acetylcholine is a facilitator of memory formation. Increasing the availability of this neurotransmitter in the brain may improve these functions. Cholinergic nootropics include acetylcholine precursors and cofactors, and acetylcholinesterase inhibitors:

-Choline - precursor of acetylcholine
-Meclofenoxate - probable precursor of acetylcholine, approved for Dementia and Alzheimer's

-Acetylcarnitine - amino acid that functions in acetylcholine production by donating the acetyl portion to the acetylcholine molecule
-Vitamin B5 - cofactor in the conversion of choline into acetylcholine

Acetylcholinesterase inhibitors
-Huperzine A

Reuptake inhibitors and enchancers
-Coluracetam - choline uptake enhancer


GABA blockers

The GABAA α5 receptor site has recently displayed memory improvements when inverse agonized.
α5IA - α5 inverse agonist
Suritozole - α5 partial inverse agonist

Glutamate activators

The AMPA transmitter and the AMPA receptors are currently being researched with significant memory improvements and possible alertness enhancement when agonized. The drug class for AMPA system modulation is called Ampakines. Although there are many in-research ones, the main ones mentioned will be the ones possibly coming to market or are significantly notable.
Some racetams have shown this activity
CX-717 - Going through FDA approval for memory-impairing illnesses
IDRA-21 - believed to improve memory by significantly enhancing long-term potentiation but used only in animals - incredibly potent
LY-503,430 - Being developed for Parkinson's but showing increase in BDNF, specifically in areas of memory and higher cognitive skills


Cyclic adenosine monophosphate is a secondary messenger that, if increased, has shown memory improvements. One common method is by decreasing the activity of phosphodiesterase-4, an enzyme that breaks down cAMP. Typical effects include wakefulness and memory enhancement.
Propentofylline - nonselective phosphodiesterase inhibitor with some neuroenhancement
Rolipram - Drug. shows alertness enhancement, long term memory improvement and neuroprotection
Mesembrine - PDE4-inhibitor with possible serotonergic activity


Serotonin is a neurotransmitter with various effects on mood and possible effects on neurogenesis. Serotonergics are substances that affect the neurotransmitter serotonin or the components of the nervous system that use serotonin. Serotonergic nootropics include serotonin precursors and cofactors, and serotonin reuptake inhibitors:
5-HTP - precursor
Tryptophan - Essential amino acid
SSRIs - Class of antidepressants that increase active serotonin levels by inhibiting its reuptake. Have also been shown to promote Neurogenesis in the hippocampus.
Tianeptine - paradoxical antidepressant, improves mood and reduces anxiety
Methamphetamine - some serotonin activity

Anti-depression, adaptogenic (antistress), and mood stabilization

Stress, depression, and depressed mood negatively affect cognitive performance. It is reasoned that counteracting and preventing depression and stress may be an effective nootropic strategy. The term adaptogen applies to most herbal anti-stress claims.
The substances below may not have been mentioned earlier on the page:
Beta blockers - anxiolytic
Kava kava - mild euphoric depressant used in relaxation
Lemon Balm - Displays adaptogen properties
Passion Flower - possible MAOI and neurotransmitter reuptake activity
Rhodiola Rosea - possible MAOI activity
St John's Wort - herbal MAOI that has been approved (in Europe) to treat mild depression
Ginseng (including Siberian ginseng) - adaptogenic effects shown
Sutherlandia frutescens - possible anti-inflammatory reducing pain from those illnesses
Tea - contains many different adaptogens
Theanine - GABAergic activity producing relaxation, also increases brain serotonin and dopamine levels
Grape seed extract - has shown some efficacy in reducing bodily stress
Adafenoxate - possible anti-anxiety effect
Valerian - possible anti-anxiety effect
Butea frondosa - possible anti-anxiety effect[10]
Gotu Kola - adaptogen and anxiolytic

Blood flow and metabolic function

Brain function is dependent on many basic processes such as the usage of ATP, removal of waste, and intake of new materials. Improving blood flow or altering these processes can benefit brain function. Vasodilators mentioned are only those which have shown, at minimum, probable mental enhancement.

Blessed Thistle - increases blood circulation, improving memory
Coenzyme q-10 - increases oxygen usage by mitochondria
Creatine - protects ATP during transport
Lipoic acid - improves oxygen usage and antioxidant recycling, possibly improving memory
Pyritinol - Drug. Similar to B vitamin Pyridoxine
Vinpocetine - increases blood circulation (vasodilator) and metabolism in the brain
Picamilon - GABA activity and blood flow improver
Ginkgo biloba - vasodilator

Nerve growth stimulation and brain cell protection

Nerves are necessary to the foundation of brain communication and their degeneracy, underperformance, or lacking can have disastrous results on brain functions. Antioxidants are frequently used to prevent oxidative stress, but do not improve brain function if that is their only activity.

Idebenone - antioxidant
Melatonin - antioxidant
Inositol - implicated in memory function, deficit linked to some psychiatric illnesses
dopamine enhancers - dopamine is an antioxidant and can enhance dendrite extension
Anticonvulsants inhibit seizure related brain malfunction if a person has seizures
Phosphatidylserine - possible membrane stabilizer

Recreational drugs

Many recreational substances that are currently illegal or heavily controlled have effects on the brain or long-term functions that are typically considered secondary to their effects on perception. Note that this list is not intended to be exhaustive. This list include substances which are illegal, or not completely illegal, but are controlled or exempt under a Drug schedule.
See also: Controlled substances act and Misuse of Drugs Act 1971

Tetrahydrocannabinol - Anxiolytic and analgesic found in cannabis. Neuroprotectant, possible Alzheimer's prevention and possible neurogenesis inducer
Amphetamine-type stimulants are described above
LSD - Psychedelic drug. At sub-recreational doses serotonin activity could alter neurogenesis and improve mood.
4-methylaminorex - similar to Modafinil but significantly more abuse potential
Most Entheogens, including hallucinogens - drugs or substances which have shown value in psychotherapy, like mescaline, MDMA, and others
MDPV - designer drug, 4x as potent as methylphenidate, greater abuse potential
Tobacco - Contains nicotine and also has significant MAOI activity

Dietary nootropics

Diet can have the greatest effect on cognition and the brain, as there are many necessary things that must be consumed. However, other substances have been linked to certain benefits, and may be predominant in certain foods.
Some regular food items contain substances with alleged nootropic benefits:

Hemp or Flax - seeds as source of omega-3 fatty acids (see essential fatty acid)
Fish - sources of omega-3 fatty acids (see essential fatty acid)
Berries - may contain high levels of antioxidants

Direct hormones

These are hormones that have activity not necessarily attributable to another specific chemical interaction, but have shown effectiveness. Only specific nootropic effects are stated.

Vasopressin - memory hormone that improves both memory encoding and recall
Pregnenolone - increases neurogenesis
Orexin - Significant wakefulness promoter

Secondary enhancers

These are substances which by themselves may not improve brain function, but may have benefits for those lacking them (in the case of hormones) or may alter the balance of neurotransmitters.

DHEA - Precursor to Estrogen and Testosterone

Unknown enhancement

Other agents purported to have nootropic effects but which do not (yet) have attributable mechanisms or clinically significant effects (but may upon refinement of administration) are mentioned here.
Nootropics with proven or purported benefits:

Bacopa monniera - enhances memory and concentration.[11] Folk use in Ayurvedic medicine purports "enhancement of curiosity".
Brahmi rasayana - improved learning and memory in mice.[12]
Ergoloid mesylates - Drug. Similar to LSD. Used against Dementia and Alzheimers
Fipexide - drug for Dementia
Gerovital H3 - famous anti-aging mixture, most effects disproven, but some mind enhancement shown
Sulbutiamine - fat soluble vitamin B1 derivative . Some shown memory improvement
Royal Jelly - Increases brain cell growth and diversity, only proven in-vitro, improbable in-vivo
Curcumin - Significant in-vitro activity, but in-vivo activity is limited by low bioavailability

Other nootropics

These substances have been linked to better cognitive function, but may not be the cause. See correlation does not imply causation
Moderate use of alcohol - Moderate drinkers tend to have better cognitive function than both abstainers and heavy drinkers.[13][14][15][16][17][18]


1. "Dorlands Medical Dictionary".
2. Lanni C, Lenzken SC, Pascale A, et al. (March 2008). "Cognition enhancers between treating and doping the mind". Pharmacol. Res. 57 (3): 196–213. doi:10.1016/j.phrs.2008.02.004. PMID 18353672.
3. a b c d Sahakian B, Morein-Zamir S (December 2007). "Professor's little helper". Nature 450 (7173): 1157–9. doi:10.1038/4501157a. PMID 18097378.
4. a b c ""Towards responsible use of cognitive-enhancing drugs by the healthy" in Nature: International Weekly Journal of Science". Retrieved December 2008.
5. a b c Malik R, Sangwan A, Saihgal R, Jindal DP, Piplani P (2007). "Towards better brain management: nootropics". Curr. Med. Chem. 14 (2): 123–31. doi:10.2174/092986707779313408. PMID 17266573.
6. Goldman P (2001). "Herbal medicines today and the roots of modern pharmacology". Ann. Intern. Med. 135 (8 Pt 1): 594–600. PMID 11601931.
7. a b McDaniel, M.A., Maier, S.F., and Einstein, G.O. (2002). "Brain-Specific Nutrients: A Memory Cure?". Psychological Science in the Public Interest (American Psychological Society) 3 (1): 957. doi:10.1016/S0899-9007(03)00024-8.
8. Gualtieri F, Manetti D, Romanelli MN, Ghelardini C (2002). "Design and study of piracetam-like nootropics, controversial members of the problematic class of cognition-enhancing drugs". Curr. Pharm. Des. 8 (2): 125–38. doi:10.2174/1381612023396582. PMID 11812254.
9. "Popping Smart Pills: The Case for Cognitive Enhancement - TIME".,8599,1869435,00.html.
10. Soman I, Mengi SA, Kasture SB (September 2004). "Effect of leaves of Butea frondosa on stress, anxiety, and cognition in rats". Pharmacol. Biochem. Behav. 79 (1): 11–6. doi:10.1016/j.pbb.2004.05.022. PMID 15388278.
11. Singh, H.K. and Dhawan, B.N. (01 Sep 1997). "Neuropsychopharmacological effects of the Ayurvedic nootropic Bacopa monniera Linn. (Brahmi)". Indian Journal of Pharmacology 29 (5): 359–65.;year=1997;volume=29;issue=5;spage=359;epage=365;aulast=Singh;type=0.
12. Joshi H, Parle M (March 2006). "Brahmi rasayana improves learning and memory in mice". Evid Based Complement Alternat Med 3 (1): 79–85. doi:10.1093/ecam/nek014. PMID 16550227. PMC: 1375237.
13. Britton A, Singh-Manoux A, Marmot M (August 2004). "Alcohol consumption and cognitive function in the Whitehall II Study". Am. J. Epidemiol. 160 (3): 240–7. doi:10.1093/aje/kwh206. PMID 15257997.
14. Launer LJ, Feskens EJ, Kalmijn S, Kromhout D (February 1996). "Smoking, drinking, and thinking. The Zutphen Elderly Study". Am. J. Epidemiol. 143 (3): 219–27. PMID 8561155.
15. Galanis DJ, Joseph C, Masaki KH, Petrovitch H, Ross GW, White L (August 2000). "A longitudinal study of drinking and cognitive performance in elderly Japanese American men: the Honolulu-Asia Aging Study". Am J Public Health 90 (8): 1254–9. PMID 10937006. PMC: 1446341.
16. Dufouil C, Ducimetière P, Alpérovitch A (September 1997). "Sex differences in the association between alcohol consumption and cognitive performance. EVA Study Group. Epidemiology of Vascular Aging". Am. J. Epidemiol. 146 (5): 405–12. PMID 9290500.
17. Rodgers B, Windsor TD, Anstey KJ, Dear KB, F Jorm A, Christensen H (September 2005). "Non-linear relationships between cognitive function and alcohol consumption in young, middle-aged and older adults: the PATH Through Life Project". Addiction 100 (9): 1280–90. doi:10.1111/j.1360-0443.2005.01158.x. PMID 16128717.
18. Anstey KJ, Windsor TD, Rodgers B, Jorm AF, Christensen H (September 2005). "Lower cognitive test scores observed in alcohol abstainers are associated with demographic, personality, and biological factors: the PATH Through Life Project". Addiction 100 (9): 1291–301. doi:10.1111/j.1360-0443.2005.01159.x. PMID 16128718.


Wednesday, October 7, 2009

List of cognitive biases

Site of the day:

A cognitive bias is a pattern of deviation in judgment that occurs in particular situations (see also cognitive distortion and the lists of thinking-related topics). Implicit in the concept of a "pattern of deviation" is a standard of comparison; this may be the judgment of people outside those particular situations, or may be a set of independently verifiable facts. The existence of some of these cognitive biases has been verified empirically in the field of psychology, others are widespread beliefs, and may themselves be a consequence of cognitive bias.

Cognitive biases are instances of evolved mental behavior. Some are presumably adaptive, for example, because they lead to more effective actions or enable faster decisions. Others presumably result from a lack of appropriate mental mechanisms, or from the misapplication of a mechanism that is adaptive under different circumstances.

Decision-making and behavioral biases

Many of these biases are studied for how they affect belief formation, business decisions, and scientific research.

Bandwagon effect — the tendency to do (or believe) things because many other people do (or believe) the same. Related to groupthink and herd behaviour.
Base rate fallacy — ignoring available statistical data in favor of particulars.
Bias blind spot — the tendency not to compensate for one's own cognitive biases.[1]
Choice-supportive bias — the tendency to remember one's choices as better than they actually were.
Confirmation bias — the tendency to search for or interpret information in a way that confirms one's preconceptions.
Congruence bias — the tendency to test hypotheses exclusively through direct testing, in contrast to tests of possible alternative hypotheses.
Contrast effect — the enhancement or diminishing of a weight or other measurement when compared with a recently observed contrasting object.
Déformation professionnelle — the tendency to look at things according to the conventions of one's own profession, forgetting any broader point of view.
Denomination effect — the tendency to spend more money when it is denominated in small amounts (e.g. coins) than large amounts (e.g. bills).[2]
Distinction bias — the tendency to view two options as more dissimilar when evaluating them simultaneously than when evaluating them separately.[3]
Endowment effect — "the fact that people often demand much more to give up an object than they would be willing to pay to acquire it".[4]
Experimenter's or Expectation bias — the tendency for experimenters to believe, certify, and publish data that agree with their expectations for the outcome of an experiment, and to disbelieve, discard, or downgrade the corresponding weightings for data that appear to conflict with those expectations.[5]
Extraordinarity bias — the tendency to value an object more than others in the same category as a result of an extraordinarity of that object that does not, in itself, change the value.
Focusing effect — prediction bias occurring when people place too much importance on one aspect of an event; causes error in accurately predicting the utility of a future outcome.
Framing — Using an approach or description of the situation or issue that is too narrow. Also framing effect — drawing different conclusions based on how data is presented.
Hyperbolic discounting — the tendency for people to have a stronger preference for more immediate payoffs relative to later payoffs, where the tendency increases the closer to the present both payoffs are.
Illusion of control — the tendency for human beings to believe they can control or at least influence outcomes that they clearly cannot.
Impact bias — the tendency for people to overestimate the length or the intensity of the impact of future feeling states.
Information bias — the tendency to seek information even when it cannot affect action.
Irrational escalation — the tendency to make irrational decisions based upon rational decisions in the past or to justify actions already taken.
Just-World Phenomenon - witnesses of an "inexplicable injustice . . . will rationalize it by searching for things that the victim might have done to deserve it"
Loss aversion — "the disutility of giving up an object is greater than the utility associated with acquiring it".[6] (see also sunk cost effects and Endowment effect).
Mere exposure effect — the tendency for people to express undue liking for things merely because they are familiar with them.
Money illusion — an irrational notion that the arbitrary values of currency, fiat or otherwise, have an actual immutable value.
Moral credential effect — the tendency of a track record of non-prejudice to increase subsequent prejudice.
Need for closure — the need to reach a verdict in important matters; to have an answer and to escape the feeling of doubt and uncertainty. The personal context (time or social pressure) might increase this bias.[7]
Neglect of probability — the tendency to completely disregard probability when making a decision under uncertainty.
Not Invented Here — the tendency to ignore that a product or solution already exists, because its source is seen as an "enemy" or as "inferior".
Omission bias — the tendency to judge harmful actions as worse, or less moral, than equally harmful omissions (inactions).
Outcome bias — the tendency to judge a decision by its eventual outcome instead of based on the quality of the decision at the time it was made.
Planning fallacy — the tendency to underestimate task-completion times.
Post-purchase rationalization — the tendency to persuade oneself through rational argument that a purchase was a good value.
Pseudocertainty effect — the tendency to make risk-averse choices if the expected outcome is positive, but make risk-seeking choices to avoid negative outcomes.
Reactance — the urge to do the opposite of what someone wants you to do out of a need to resist a perceived attempt to constrain your freedom of choice.
Restraint bias - the tendency to overestimate one's ability to show restraint in the face of temptation.
Selective perception — the tendency for expectations to affect perception.
Semmelweis reflex — the tendency to reject new evidence that contradicts an established paradigm.[8]
Status quo bias — the tendency for people to like things to stay relatively the same (see also loss aversion, endowment effect, and system justification).[9]
Von Restorff effect — the tendency for an item that "stands out like a sore thumb" to be more likely to be remembered than other items.
Wishful thinking — the formation of beliefs and the making of decisions according to what is pleasing to imagine instead of by appeal to evidence or rationality.
Zero-risk bias — preference for reducing a small risk to zero over a greater reduction in a larger risk.

Biases in probability and belief

Many of these biases are often studied for how they affect business and economic decisions and how they affect experimental research.

Ambiguity effect — the avoidance of options for which missing information makes the probability seem "unknown".
Anchoring effect — the tendency to rely too heavily, or "anchor," on a past reference or on one trait or piece of information when making decisions (also called "insufficient adjustment").
Attentional bias — neglect of relevant data when making judgments of a correlation or association.
Authority bias — the tendency to value an ambiguous stimulus (e.g., an art performance) according to the opinion of someone who is seen as an authority on the topic.
Availability heuristic — estimating what is more likely by what is more available in memory, which is biased toward vivid, unusual, or emotionally charged examples.
Availability cascade — a self-reinforcing process in which a collective belief gains more and more plausibility through its increasing repetition in public discourse (or "repeat something long enough and it will become true").
Belief bias — an effect where someone's evaluation of the logical strength of an argument is biased by the believability of the conclusion.
Clustering illusion — the tendency to see patterns where actually none exist.
Capability bias — The tendency to believe that the closer average performance is to a target, the tighter the distribution of the data set.
Conjunction fallacy — the tendency to assume that specific conditions are more probable than general ones.
Disposition effect — the tendency to sell assets that have increased in value but hold assets that have decreased in value.
Gambler's fallacy — the tendency to think that future probabilities are altered by past events, when in reality they are unchanged. Results from an erroneous conceptualization of the normal distribution. For example, "I've flipped heads with this coin five times consecutively, so the chance of tails coming out on the sixth flip is much greater than heads."
Hawthorne effect — the tendency of people to perform or perceive differently when they know that they are being observed.
Hindsight bias — sometimes called the "I-knew-it-all-along" effect, the inclination to see past events as being predictable.
Illusory correlation — beliefs that inaccurately suppose a relationship between a certain type of action and an effect.[10]
Ludic fallacy — the analysis of chance-related problems according to the belief that the unstructured randomness found in life resembles the structured randomness found in games, ignoring the non-gaussian distribution of many real-world results.
Neglect of prior base rates effect — the tendency to neglect known odds when reevaluating odds in light of weak evidence.
Observer-expectancy effect — when a researcher expects a given result and therefore unconsciously manipulates an experiment or misinterprets data in order to find it (see also subject-expectancy effect).
Optimism bias — the systematic tendency to be over-optimistic about the outcome of planned actions.
Ostrich effect — ignoring an obvious (negative) situation.
Overconfidence effect — excessive confidence in one's own answers to questions. For example, for certain types of question, answers that people rate as "99% certain" turn out to be wrong 40% of the time.
Positive outcome bias — a tendency in prediction to overestimate the probability of good things happening to them (see also wishful thinking, optimism bias, and valence effect).
Pareidolia — vague and random stimulus (often an image or sound) are perceived as significant, e.g., seeing images of animals or faces in clouds, the man in the moon, and hearing hidden messages on records played in reverse.
Primacy effect — the tendency to weigh initial events more than subsequent events.
Recency effect — the tendency to weigh recent events more than earlier events (see also peak-end rule).
Disregard of regression toward the mean — the tendency to expect extreme performance to continue.
Selection bias — a distortion of evidence or data that arises from the way that the data are collected.
Stereotyping — expecting a member of a group to have certain characteristics without having actual information about that individual.
Subadditivity effect — the tendency to judge probability of the whole to be less than the probabilities of the parts.
Subjective validation — perception that something is true if a subject's belief demands it to be true. Also assigns perceived connections between coincidences.
Telescoping effect — the effect that recent events appear to have occurred more remotely and remote events appear to have occurred more recently.
Texas sharpshooter fallacy — the fallacy of selecting or adjusting a hypothesis after the data is collected, making it impossible to test the hypothesis fairly. Refers to the concept of firing shots at a barn door, drawing a circle around the best group, and declaring that to be the target.

Social biases

Most of these biases are labeled as attributional biases.

Actor-observer bias — the tendency for explanations of other individuals' behaviors to overemphasize the influence of their personality and underemphasize the influence of their situation (see also fundamental attribution error). However, this is coupled with the opposite tendency for the self in that explanations for our own behaviors overemphasize the influence of our situation and underemphasize the influence of our own personality.
Egocentric bias — occurs when people claim more responsibility for themselves for the results of a joint action than an outside observer would.
Forer effect (aka Barnum Effect) — the tendency to give high accuracy ratings to descriptions of their personality that supposedly are tailored specifically for them, but are in fact vague and general enough to apply to a wide range of people. For example, horoscopes.
False consensus effect — the tendency for people to overestimate the degree to which others agree with them.
Fundamental attribution error — the tendency for people to over-emphasize personality-based explanations for behaviors observed in others while under-emphasizing the role and power of situational influences on the same behavior (see also actor-observer bias, group attribution error, positivity effect, and negativity effect).
Halo effect — the tendency for a person's positive or negative traits to "spill over" from one area of their personality to another in others' perceptions of them (see also physical attractiveness stereotype).
Herd instinct — Common tendency to adopt the opinions and follow the behaviors of the majority to feel safer and to avoid conflict.
Illusion of asymmetric insight — people perceive their knowledge of their peers to surpass their peers' knowledge of them.
Illusion of transparency — people overestimate others' ability to know them, and they also overestimate their ability to know others.
Illusory superiority — overestimating one's desirable qualities, and underestimating undesirable qualities, relative to other people. Also known as Superiority bias (also known as "Lake Wobegon effect", "better-than-average effect", "superiority bias", or Dunning-Kruger effect).
Ingroup bias — the tendency for people to give preferential treatment to others they perceive to be members of their own groups.
Just-world phenomenon — the tendency for people to believe that the world is just and therefore people "get what they deserve."
Notational bias — a form of cultural bias in which a notation induces the appearance of a nonexistent natural law.
Outgroup homogeneity bias — individuals see members of their own group as being relatively more varied than members of other groups.
Projection bias — the tendency to unconsciously assume that others share the same or similar thoughts, beliefs, values, or positions.
Self-serving bias (also called "behavioral confirmation effect") — the tendency to claim more responsibility for successes than failures. It may also manifest itself as a tendency for people to evaluate ambiguous information in a way beneficial to their interests (see also group-serving bias).
Self-fulfilling prophecy — the tendency to engage in behaviors that elicit results which will (consciously or not) confirm existing attitudes.[11]
System justification — the tendency to defend and bolster the status quo. Existing social, economic, and political arrangements tend to be preferred, and alternatives disparaged sometimes even at the expense of individual and collective self-interest. (See also status quo bias.)
Trait ascription bias — the tendency for people to view themselves as relatively variable in terms of personality, behavior and mood while viewing others as much more predictable.
Ultimate attribution error — Similar to the fundamental attribution error, in this error a person is likely to make an internal attribution to an entire group instead of the individuals within the group.

Memory errors

Further information: Memory bias

Consistency bias — incorrectly remembering one's past attitudes and behaviour as resembling present attitudes and behaviour.

Cryptomnesia — a form of misattribution where a memory is mistaken for imagination.
Egocentric bias — recalling the past in a self-serving manner, e.g. remembering one's exam grades as being better than they were, or remembering a caught fish as being bigger than it was
False memory — confusion of imagination with memory, or the confusion of true memories with false memories.
Hindsight bias — filtering memory of past events through present knowledge, so that those events look more predictable than they actually were; also known as the 'I-knew-it-all-along effect'.
Reminiscence bump — the effect that people tend to recall more personal events from adolescence and early adulthood than from other lifetime periods.
Rosy retrospection — the tendency to rate past events more positively than they had actually rated them when the event occurred.
Self-serving bias — perceiving oneself responsible for desirable outcomes but not responsible for undesirable ones.
Suggestibility — a form of misattribution where ideas suggested by a questioner are mistaken for memory.

Common theoretical causes of some cognitive biases

Attribute substitution – making a complex, difficult judgement by unconsciously substituting an easier judgement[12]
Attribution theory, especially:
Cognitive dissonance, and related:
-Impression management
-Self-perception theory
Heuristics, including:
-Availability heuristic – estimating what is more likely by what is more available in memory, which is biased toward vivid, unusual, or emotionally charged examples[10]
-Representativeness heuristic – judging probabilities on the basis of resemblance[10]
-Affect heuristic – basing a decision on an emotional reaction rather than a calculation of risks and benefits [13]
Adaptive bias

See also

Attribution theory
Black swan theory
List of common misconceptions
List of fallacies
List of memory biases
List of topics related to public relations and propaganda
Logical fallacy
Media bias
Psychological immune system
System justification
Systematic bias


1. Pronin, Emily; Matthew B. Kugler (July 2007). "Valuing thoughts, ignoring behavior: The introspection illusion as a source of the bias blind spot". Journal of Experimental Social Psychology (Elsevier) 43 (4): 565-578. doi:10.1016/j.jesp.2006.05.011. ISSN 0022-1031.
2. Why We Spend Coins Faster Than Bills by Chana Joffe-Walt. All Things Considered, 12 May 2009.
3. (Hsee & Zhang, 2004)
4. (Kahneman, Knetsch, and Thaler 1991: 193) Richard Thaler coined the term "endowment effect."
5. M. Jeng, "A selected history of expectation bias in physics", American Journal of Physics 74 578-583 (2006)
6. (Kahneman, Knetsch, and Thaler 1991: 193) Daniel Kahneman, together with Amos Tversky, coined the term "loss aversion."
7. Kruglanski, 1989; Kruglanski & Webster, 1996
8. Edwards, W. (1968). Conservatism in human information processing. In: B. Kleinmutz (Ed.), Formal Representation of Human Judgment. (pp. 17-52). New York: John Wiley and Sons.
9. (Kahneman, Knetsch, and Thaler 1991: 193)
10 a b c Tversky, Amos; Daniel Kahneman (September 27, 1974). "Judgment under Uncertainty: Heuristics and Biases". Science (American Association for the Advancement of Science) 185 (4157): 1124–1131.
11. Darley, John M.; Paget H. Gross (2000). "A Hypothesis-Confirming Bias in Labelling Effects". in Charles Stangor. Stereotypes and prejudice: essential readings. Psychology Press. p. 212. ISBN 9780863775895.
12. Kahneman, Daniel; Shane Frederick (2002). "Representativeness Revisited: Attribute Substitution in Intuitive Judgment". in Thomas Gilovich, Dale Griffin, Daniel Kahneman. Heuristics and Biases: The Psychology of Intuitive Judgment. Cambridge: Cambridge University Press. pp. 49–81. ISBN 9780521796798. OCLC 47364085.
13. Slovic, Paul; Melissa Finucane, Ellen Peters, Donald G. MacGregor (2002). "The Affect Heuristic". in Thomas Gilovich, Dale Griffin, Daniel Kahneman. Heuristics and Biases: The Psychology of Intuitive Judgment. Cambridge University Press. pp. 397-420. ISBN 97805219796798.


Enjoy the list :)

Tuesday, October 6, 2009

Energy And Information

Site of the day:

The Dance of Particles and Bits

In the 20th and 21st centuries, computer science and physics have teamed up to explore the enigmatic relationship between energy and information.

Both energy and information are among the most difficult concepts to understand because they are so fundamental to the nature of the universe. Everything described in physics ultimately comes down to energy. For example, most people know of Einstein's famous equation, mass times the square of the speed of light equals energy. Matter is energy.

In fact, matter is a stored form of energy. Matter is a combination of energy and information. On a quantum level, all particles can be described by bits of information. How the information is mapped to energy is dependent on the observer. The observer need not be human either, it could be a neighboring particle.

In recent decades several new theories have developed in parallel with the rise of computer science, such as emergence, and complexity theory. The most revolutionary of these is the idea that the universe, and all matter in it, are self-computing. In a closed system of two particles (they could be anything), the particles can interact through the four fundamental forces. How they interact depends on what kind of particles they are the forces that are available to them. Information and energy can be exchanged, and the two particles will quickly come to a state of equilibrium. Since particles follow a different set of rules than macroscopic objects like billiard balls, this equilibrium isn't a state of rest, but rather a pattern.

This is illustrated to great effect with cellular automata, a simplified two-dimensional analog of particle systems. In a system of cellular automata, also known as the "Game of Life", there is a grid of cells. Each cell can be on or off, and the cells in the grid are given a set of rules to follow. For instance, if a cell is on, and three of it's neighboring cells are on, it must turn off. If a cell is off, and three of its neighbors are off, it must turn on. Information is exchanged between that cell and it's neighbors. Since all of the cells are constantly calculating how other cells are affecting them, the system will change rapidly, but it will usually settle into an oscillating pattern.

The same is true for systems of particles, though it is complicated by quantum uncertainty, and probabilities are important. Large systems of particles are best analyzed with statistics, though at the macroscopic scale the weirdness of quantum mechanics evens out and information systems are more predictable.

by Katharine M. J. Osborne (