Sunday, April 30, 2023

DISC Model - Marston types

William Moulton Marston was a psychologist who contributed to developing the DISC theory, a model used to describe human behavior. The DISC theory consists of four primary behavior types: Dominance, Influence, Steadiness, and Conscientiousness.

  1. Dominance (D): People with high Dominance are assertive, decisive, and driven. They like to take charge and be in control of situations. They are goal-oriented and may be perceived as aggressive or confrontational.

  2. Influence (I): Individuals with high Influence are sociable, talkative, and outgoing. They enjoy interacting with others and have a natural ability to persuade or inspire others. They are often seen as enthusiastic, optimistic, and charismatic.

  3. Steadiness (S): People with high Steadiness are calm, dependable, and patient. They value stability and consistency, preferring to work at a steady pace. They are good listeners, empathetic, and may avoid conflicts.

  4. Conscientiousness (C): Individuals with high Conscientiousness are meticulous, detail-oriented, and organized. They value accuracy and precision and follow the rules and procedures closely. They are often seen as analytical, careful, and systematic.

It's worth noting that the DISC theory does not label any behavior type as inherently "good" or "bad." Instead, it highlights how individuals approach tasks, communicate, and interact with others. Understanding these behavior types can help improve communication, teamwork, and personal development.



The Enneagram is a human personality model based on nine interconnected personality types. It is a system that combines ancient spiritual wisdom with modern psychology to provide insights into different individuals' motivations, fears, and desires.

The word "enneagram" comes from the Greek words "ennea" (nine) and "gramma" (something written or drawn).

Concepts and Components:

The nine personality types: The Enneagram identifies nine distinct personality types from 1 to 9. Each type has a unique set of characteristics, strengths, and weaknesses.

Wings: Each personality type has two adjacent types called "wings." A person's wing is thought to influence their core type, creating a more nuanced and unique personality.

Triads: The nine types are grouped into three triads based on their primary emotional orientation: Head (Types 5, 6, 7), Heart (Types 2, 3, 4), and Body (Types 8, 9, 1).

Levels of development: Within each type, there are nine levels of development, ranging from healthy to unhealthy expressions of the type's traits.

Integration and disintegration: Each type has paths of integration and disintegration, indicating how they behave when growing and under stress, respectively.

Origins and Authors:

The Enneagram has a complex history, with its origins tracing back to multiple sources, such as the teachings of the Desert Fathers, the Sufi tradition, and the Kabbalah. The modern Enneagram we know today was developed in the mid-20th century by Bolivian-born philosopher Óscar Ichazo and further refined by Chilean psychiatrist Claudio Naranjo.

Relation with the Myers-Briggs Type Indicator (MBTI):

While the Enneagram and the MBTI are personality typology systems, they have different focuses and approaches. The MBTI is based on Carl Jung's theories of cognitive functions and categorizes people into 16 types based on their preferences in four dichotomies: Extraversion/Introversion, Sensing/Intuition, Thinking/Feeling, and Judging/Perceiving. Conversely, the Enneagram focuses on core motivations and fears, providing insights into an individual's emotional and psychological dynamics. Although some correlations between the two systems can be found, they are not directly related and offer different perspectives on personality.

Professional Reputation and Results:

The Enneagram has gained popularity in various fields, such as personal growth, business, counseling, and spiritual development. Many people find it helpful in understanding themselves and others, improving communication, and promoting self-awareness. However, it is essential to remember that the Enneagram is a tool and should be used alongside other assessments and professional guidance.


Lack of scientific validity: Critics argue that the Enneagram lacks rigorous scientific research to support its claims and relies heavily on anecdotal evidence and subjective interpretations.

Over-simplification of human personality: Some critics contend that dividing people into nine distinct types oversimplifies the complexity of human personalities.

Potential for self-limiting beliefs: Categorizing oneself into a specific type can lead to self-limiting beliefs and behaviors based on the traits associated with that type, potentially hindering personal growth and development.

Despite these criticisms, the Enneagram remains a widespread personal and professional growth tool. It is essential to approach the Enneagram with an open mind and use it as a starting point for self-exploration and understanding rather than an absolute measure of one's personality.

The Enneagram consists of nine interconnected personality types, each with unique characteristics. Here, we will describe the nine types and their associated factors, including their primary motivations, basic fears, and key traits. Additionally, we'll provide an example of a hypothetical individual's Enneagram results.


Type 1 - The Perfectionist (or The Reformer)

Primary Motivation: To be good, ethical, and morally upright

Basic Fear: Being corrupt or imperfect

Key Traits: Responsible, disciplined, orderly, critical, and principled


Type 2 - The Helper (or The Giver)

Primary Motivation: To be loved and appreciated

Basic Fear: Being unloved or unwanted

Key Traits: Caring, generous, people-pleasing, empathetic, and possessive


Type 3 - The Achiever (or The Performer)

Primary Motivation: To be successful, admired, and respected

Basic Fear: Being worthless or a failure

Key Traits: Driven, adaptable, image-conscious, goal-oriented, and competitive


Type 4 - The Individualist (or The Romantic)

Primary Motivation: To be unique, authentic, and understood

Basic Fear: Having no identity or personal significance

Key Traits: Sensitive, introspective, moody, creative, and self-absorbed


Type 5 - The Investigator (or The Observer)

Primary Motivation: To be knowledgeable and competent

Basic Fear: Being helpless or incapable

Key Traits: Analytical, detached, private, curious, and independent


Type 6 - The Loyalist (or The Skeptic)

Primary Motivation: To have security and support

Basic Fear: Being abandoned or unsupported

Key Traits: Responsible, cautious, committed, anxious, and suspicious


Type 7 - The Enthusiast (or The Adventurer)

Primary Motivation: To be happy, satisfied, and content

Basic Fear: Being deprived or trapped in pain

Key Traits: Spontaneous, fun-loving, versatile, scattered, and impulsive


Type 8 - The Challenger (or The Protector)

Primary Motivation: To be powerful and in control

Basic Fear: Being harmed or controlled by others

Key Traits: Assertive, decisive, confrontational, protective, and dominating


Type 9 - The Peacemaker (or The Mediator)

Primary Motivation: To maintain peace and harmony

Basic Fear: Loss of connection or fragmentation

Key Traits: Easygoing, supportive, accommodating, conflict-avoidant, and passive


Example Enneagram result: 

In this hypothetical example, let's consider a person named Sarah. After completing an Enneagram assessment, she discovers she is a Type 2, The Helper, with a strong 3 wing (Type 2w3). This means that Sarah's core personality is driven by the desire to be loved and appreciated, while her adjacent wing, Type 3, adds ambition and adaptability to her profile.

As a Type 2w3, Sarah will likely be warm, empathetic, and generous in her relationships. She enjoys helping others and often goes out of her way to support her friends and family. However, her Type 3 wing makes her more image-conscious and success-driven than a typical Type 2, as she also seeks admiration and respect from others. In times of stress, Sarah may move towards the disintegration point of Type 8, becoming more assertive and confrontational. Conversely, when she experiences personal growth, Sarah may move towards the integration point of Type 4, embracing her authentic emotions and developing a stronger sense of identity.

It's important to note that Enneagram results should be taken as a starting point for self-exploration and understanding rather than an absolute measure of one's personality. By learning about her Enneagram type, Sarah can gain insights into her motivations, fears, and strengths. This knowledge can help her better understand her behavior patterns, improve relationships, and work on personal growth.

Sarah can also explore the other aspects of the Enneagram, such as her triad (in her case, the Heart triad), which can provide further insights into her emotional orientation. Additionally, she can examine her levels of development within her type to identify areas where she may need to grow or where she is already thriving.

Enneagram results can offer valuable insights into an individual's personality, motivations, and fears. These insights can foster personal growth, improve communication, and enhance relationships. It's essential to approach the Enneagram with an open mind and use it as a tool for self-exploration and understanding rather than a definitive label or categorization of one's personality.




  •       Riso, D. R., & Hudson, R. (1996). Personality types: Using the Enneagram for self-discovery. Houghton Mifflin Harcourt. 

This book provides an in-depth overview of the nine Enneagram personality types and offers guidance on using the Enneagram for personal growth and self-discovery. 

  • ·   Palmer, H. (1991). The Enneagram: Understanding yourself and the others in your life. HarperSanFrancisco.

Helen Palmer's book explores the Enneagram's psychological and spiritual dimensions, offering insights into the types' motivations, fears, and potential for growth. 

  • ·    Naranjo, C. (1994). Character and neurosis: An integrative view of personality through the Enneagram and psychodynamic theory. Gateways/IDHHB Publishing. 

Claudio Naranjo, one of the key figures in the development of the modern Enneagram, connects the Enneagram system to psychodynamic theory and explores the neurotic aspects of each type. 

  • ·         Riso, D. R., & Hudson, R. (2003). Understanding the Enneagram: The practical guide to personality types. Houghton Mifflin Harcourt. 

This practical guide provides detailed descriptions of the nine types, including their wings, levels of development, and paths of integration and disintegration. 

  • ·         Chestnut, B. (2013). The complete Enneagram: 27 paths to greater self-knowledge. She Writes Press. 

Beatrice Chestnut's book extensively explores the Enneagram, including the subtypes, which are based on the three instinctual drives: self-preservation, social, and sexual (one-to-one).

These sources comprehensively understand the Enneagram's history, development, and practical applications. By exploring these books, you can gain a more profound knowledge of the Enneagram system and how it can be used for personal growth, self-discovery, and improved relationships.

Locus of Control

 By: Mariano Bernardez

Locus of control is a psychological concept that refers to how individuals believe they control events. Individuals with an internal locus of control believe they can influence the outcomes of events through their actions. In contrast, those with an external locus of control attribute the outcomes to external factors, such as luck or the actions of others. This concept was first introduced by Rotter (1966).

 Origins and Authors:

Julian B. Rotter, a prominent social learning theorist, developed the locus of control concept in 1966. Rotter's work in social learning theory served as a foundation for developing the locus of control as a measurable construct (Rotter, 1966).


Applications and Results:

Locus of control has been widely applied in various fields, such as education, health, and organizational behavior. For instance, students with an internal locus of control tend to perform better academically because they believe they have control over their learning (Gifford et al., 2006). Similarly, employees with an internal locus of control tend to demonstrate higher job satisfaction and organizational commitment, as they believe their efforts contribute to their success (Judge & Bono, 2001). In health psychology, an internal locus of control has been associated with better health outcomes, as individuals are more likely to engage in healthy behaviors (Wallston et al., 1978).


Cultural Behavior:

Locus of control has also been studied in relation to cultural differences. Research has shown that people from individualistic cultures tend to have a higher internal locus of control, while those from collectivist cultures exhibit a higher external locus of control (Spector et al., 2001). Cultural values can explain this; individualistic cultures emphasize personal autonomy, whereas collectivist cultures stress the importance of external factors, such as family and social groups.



Despite its widespread use, the locus of control concept has been criticized. One major critique is the oversimplification of the internal-external dimension, as it does not account for the complexity of human behavior (Lefcourt, 1982). Another criticism is the cultural bias present in the initial development of the concept, as it was primarily based on Western cultures, which may limit its applicability to non-Western contexts (Spector et al., 2001).




Gifford, D. D., Briceno-Perriott, J., & Mianzo, F. (2006). Locus of control: Academic achievement and retention in a sample of university first-year students. Journal of College Admission, 191, 18-25.

Judge, T. A., & Bono, J. E. (2001). Relationship of core self-evaluations traits—self-esteem, generalized self-efficacy, locus of control, and emotional stability—with job satisfaction and job performance: A meta-analysis. Journal of Applied Psychology, 86(1), 80-92. doi:10.1037/0021-9010.86.1.80

Lefcourt, H. M. (1982). Locus of control: Current trends in theory and research (2nd ed.). Hillsdale, NJ: Lawrence Erlbaum Associates.

Rotter, J. B. (1966). Generalized expectancies for internal versus external control of reinforcement. Psychological Monographs: General and Applied, 80(1), 1-28. doi:10.1037/h0092976

Spector, P. E., Cooper, C. L., & Sparks, K. (2001). An international study of the psychometric properties of the Hofstede Values



The Rotter's test and its evaluation and interpretation

Rotter's Internal-External Locus of Control Scale (I-E Scale) is a forced-choice test composed of 29 items, 23 are designed to measure locus of control, and 6 are filler items to reduce response bias.

Examples of Rotter's I-E Scale questions include:

When you make plans, do you usually:

a) Plan on things working out the way you want them to

b) Feel uncertain that they will work out as planned

Do you believe that:

a) Most people have control over their own lives

b) What happens to people is mostly a matter of luck

Each item consists of two statements, one reflecting an internal locus of control (e.g., "a") and the other reflecting an external locus of control (e.g., "b"). Participants must choose the statement that best represents their belief.


Evaluation and Interpretation:

To evaluate the I-E Scale, the test administrator calculates a total score for each participant based on the number of internal locus of control responses. The total score ranges from 0 to 23, with higher scores indicating a stronger external locus of control and lower scores indicating a stronger internal locus of control. No absolute cutoff score classifies a person as having an internal or external locus of control; the scores are generally considered on a continuum.

t is essential to consider the I-E Scale's limitations when interpreting the results. The test does not provide an in-depth assessment of the specific areas of control beliefs but offers a general overview of a person's locus of control. Furthermore, cultural differences, situational factors, and response biases can influence the scores, so they should not be interpreted in isolation. Instead, it is advised to combine the test results with other sources of information, such as interviews, observations, or additional psychological tests, to gain a more comprehensive understanding of an individual's locus of control.

Culture and Civilization

 Culture and civilization -concepts

Here are ten influential definitions of culture from various sources:

 Tylor, E. B. (1871). Primitive Culture. London: John Murray.

"Culture or Civilization, taken in its wide ethnographic sense, is that complex whole which includes knowledge, belief, art, morals, law, custom, and any other capabilities and habits acquired by man as a member of society." 

Williams, R. (1983). Keywords: A vocabulary of culture and society. London: Fontana Press.

"Culture is one of the two or three most complicated words in the English language." 

Geertz, C. (1973). The Interpretation of Cultures. New York: Basic Books.

"Man is an animal suspended in webs of significance he himself has spun; I take culture to be those webs." 

Kroeber, A. L., & Kluckhohn, C. (1952). Culture: A critical review of concepts and definitions. Cambridge, MA: Peabody Museum.

"Culture consists of patterns, explicit and implicit, of and for behavior acquired and transmitted by symbols, constituting the distinctive achievements of human groups, including their embodiments in artifacts." 

Boas, F. (1940). Race, Language, and Culture. New York: Macmillan.

"Culture embraces all the manifestations of social habits of a community, the reactions of the individual as affected by the habits of the group in which he lives, and the product of human activities as determined by these habits." 

Herskovits, M. J. (1948). Man and his Works: The Science of Cultural Anthropology. New York: A.A. Knopf.

"Culture is the man-made part of the environment." 

Linton, R. (1945). The Cultural Background of Personality. New York: Appleton-Century-Crofts.

"The culture of a society is the way of life of its members; the collection of ideas and habits which they learn, share, and transmit from generation to generation." 

White, L. A. (1959). The Concept of Culture. American Anthropologist, 61(2), 227-251.

"Culture is an organization of phenomena which includes tools, implements, utensils, customs, codes, institutions, ideas, and works of art, as well as the modes of behavior characteristic of a given human society." 

Malinowski, B. (1944). A Scientific Theory of Culture and Other Essays. Chapel Hill: The University of North Carolina Press.

"Culture is the integral whole of all socially conditioned and socially generated phenomena."


Hofstede, G. (1997). Cultures and Organizations: Software of the Mind. New York: McGraw-Hill.

"Culture is the collective programming of the mind that distinguishes the members of one group or category of people from others." 

The difference between culture and civilization is that culture refers to the shared beliefs, values, norms, customs, and practices that define a particular society. In contrast, civilization refers to a more advanced stage of human social development characterized by complex social, political, and economic systems and the growth of cities, arts, and sciences.

Arnold Toynbee (1889-1975) was a British historian who proposed a history theory in his work "A Study of History." He identified 21 significant civilizations throughout history and believed civilizations pass through genesis, growth, breakdown, and disintegration

Toynbee argued that the rise and fall of civilizations could be attributed to their ability to respond creatively to challenges posed by their environment, other societies, or internal factors.

Bernard Lewis (1916-2018) was a British-American historian specializing in Oriental studies and Islamic history. His work on the relationship between Western and Islamic civilizations highlighted the historical, cultural, and religious differences that have shaped their interactions. Lewis argued that the decline of Islamic civilization was due to internal factors, such as the failure to modernize and adapt to new challenges, rather than external pressures from the West.


Francis Fukuyama (born 1952) is an American political scientist and economist best known for his book "The End of History and the Last Man." Fukuyama argued that the spread of liberal democracy and free-market capitalism signaled the endpoint of humanity's sociocultural evolution and the universalization of Western liberal democracy as the final form of human government. This perspective has been criticized for its Western-centric and deterministic outlook.

Samuel Huntington (1927-2008) was an American political scientist best known for his book "The Clash of Civilizations and the Remaking of World Order." Huntington argued that future conflicts would primarily occur between different civilizations rather than between nation-states. 

Mariano Bernardez analyzes and discusses several culture and civilization models in the following paper -from Toynbee, Huntington, and Fukuyama to Trompenaars and Hofstede. He uses these two last models to compare multiple countries, US states, and US subcultures in a more in-depth paper:


Tuesday, January 14, 2020

Nudge: Improving Decisions About Health, Wealth, and Happiness - Richard Thaler (2017)

A nudge, as we will use the term, is any aspect of the choice architecture that alters people’s behavior in a predictable way without forbidding any options or significantly changing their economic incentives.

Humans and Econs: Why Nudges Can Help

Those who reject paternalism often claim that human beings do a terrific job of making choices, and if not terrific, certainly better than anyone else would do (especially if that someone else works for the government).

Whether or not they have ever studied economics, many people seem at least implicitly committed to the idea of homo economicus, or economic man— the notion that each of us thinks and chooses unfailingly well, and thus fits within the textbook picture of human beings offered by economists.

If you look at economics textbooks, you will learn that homo economicus can think like Albert Einstein, store as much memory as IBM’s Big Blue, and exercise the willpower of Mahatma Gandhi. Really.

But the folks that we know are not like that.

Real people have trouble with long division if they don’t have a calculator, sometimes forget their spouse’s birthday, and have a hangover on New Year’s Day. They are not homo economicus; they are homo sapiens.

To keep our Latin usage to a minimum we will hereafter refer to these imaginary and real species as Econs and Humans.

Consider the issue of obesity.

Rates of obesity in the United States are now approaching 20 percent, and more than 60 percent of Americans are considered either obese or overweight.

There is overwhelming evidence that obesity increases risks of heart disease and diabetes, frequently leading to premature death. It would be quite fantastic to suggest that everyone is choosing the right diet, or a diet that is preferable to what might be produced with a few nudges.

Of course, sensible people care about the taste of food, not simply about health, and eating is a source of pleasure in and of itself.

We do not claim that everyone who is overweight is necessarily failing to act rationally, but we do reject the claim that all or almost all Americans are choosing their diet optimally.

What is true for diets is true for other risk- related behavior, including smoking and drinking, which produce more than five hundred thousand premature deaths each year.

With respect to diet, smoking, and drinking, people’s current choices cannot reasonably be claimed to be the best means of promoting their well- being. Indeed, many smokers, drinkers, and overeaters are willing to pay third parties to help them make better decisions.

But our basic source of information here is the emerging science of choice, consisting of careful research by social scientists over the past four decades.

That research has raised serious questions about the rationality of many judgments and decisions that people make.

To qualify as Econs, people are not required to make perfect forecasts (that would require omniscience), but they are required to make unbiased forecasts.

That is, the forecasts can be wrong, but they can’t be systematically wrong in a predictable direction.

Unlike Econs, Humans predictably err.

Take, for example, the “planning fallacy”— the systematic tendency toward unrealistic optimism about the time it takes to complete projects.

It will come as no surprise to anyone who has ever hired a contractor to learn that everything takes longer than you think, even if you know about the planning fallacy. Hundreds of studies confirm that human forecasts are flawed and biased. Human decision making is not so great either.

Again, to take just one example, consider what is called the “status quo bias,” a fancy name for inertia. For a host of reasons, which we shall explore, people have a strong tendency to go along with the status quo or default option.

When you get a new cell phone, for example, you have a series of choices to make.

 The fancier the phone, the more of these choices you face, from the background to the ring sound to the number of times the phone rings before the caller is sent to voice mail.

The manufacturer has picked one option as the default for each of these choices. Research shows that whatever the default choices are, many people stick with them, even when the stakes are much higher than choosing the noise your phone makes when it rings. Two important lessons can be drawn from this research.

First, never underestimate the power of inertia.

Second, that power can be harnessed.

Libertarian Paternalism

If, all things considered, you think that Carolyn should take the opportunity to nudge the kids toward food that is better for them, Option 1, then we welcome you to our new movement: libertarian paternalism.

 We are keenly aware that this term is not one that readers will find immediately endearing.

Both words are somewhat off-putting, weighted down by stereotypes from popular culture and politics that make them unappealing to many. Even worse, the concepts seem to be contradictory.

Why combine two reviled and contradictory concepts?

We argue that if the terms are properly understood, both concepts reflect common sense—and they are far more attractive together than alone.

The problem with the terms is that they have been captured by dogmatists.

The libertarian aspect of our strategies lies in the straightforward insistence that, in general, people should be free to do what they like—and to opt out of undesirable arrangements if they want to do so.

To borrow a phrase from the late Milton Friedman, libertarian paternalists urge that people should be “free to choose.”

We strive to design policies that maintain or increase freedom of choice.

When we use the term libertarian to modify the word paternalism, we simply mean liberty-preserving. And when we say liberty-preserving, we really mean it.

Libertarian paternalists want to make it easy for people to go their own way; they do not want to burden those who want to exercise their freedom.

The paternalistic aspect lies in the claim that it is legitimate for choice architects to try to influence people’s behavior in order to make their lives longer, healthier, and better. In other words, we argue for self-conscious efforts, by institutions in the private sector and also by government, to steer people’s choices in directions that will improve their lives.

In our understanding, a policy is “paternalistic” if it tries to influence choices in a way that will make choosers better off, as judged by themselves.

Drawing on some well-established findings in social science, we show that in many cases, individuals make pretty bad decisions—decisions they would not have made if they had paid full attention and possessed complete information, unlimited cognitive abilities, and complete self- control.

Libertarian paternalism is a relatively weak, soft, and nonintrusive type of paternalism because choices are not blocked, fenced off, or significantly burdened.

If people want to smoke cigarettes, to eat a lot of candy, to choose an unsuitable health care plan, or to fail to save for retirement, libertarian paternalists will not force them to do otherwise— or even make things hard for them.

Still, the approach we recommend does count as paternalistic, because private and public choice architects are not merely trying to track or to implement people’s anticipated choices. Rather, they are self- consciously attempting to move people in directions that will make their lives better.

Thinking, Fast and Slow - System One and Two - Daniel Kahneman (2012)

Two Systems

The distinction between fast and slow thinking has been explored by many psychologists over the last twenty-five years. For reasons that I explain more fully in the next chapter, I describe mental life by the metaphor of two agents, called System 1 and System 2, which respectively produce fast and slow thinking.

It emerges from recent research, the intuitive System 1 is more influential than your experience tells you, and it is the secret author of many of the choices and judgments you make.

System 1 operates automatically and quickly, with little or no effort and no sense of voluntary control. 

System 2 allocates attention to the effortful mental activities that demand it, including complex computations. 

The operations of System 2 are often associated with the subjective experience of agency, choice, and concentration. 

The labels of System 1 and System 2 are widely used in psychology, but I go further than most in this book, which you can read as a psychodrama with two characters. When we think of ourselves, we identify with System 2, the conscious, reasoning self that has beliefs, makes choices, and decides what to think about and what to do. 

Although System 2 believes itself to be where the action is, the automatic System 1 is the hero of the book. I describe System 1 as effortlessly originating impressions and feelings that are the main sources of the explicit beliefs and deliberate choices of System 2.

 The highly diverse operations of System 2 have one feature in common: they require attention and are disrupted when attention is drawn away.

System 2 has some ability to change the way System 1 works, by programming the normally automatic functions of attention and memory.

Scarcity - Mullainathan, Sendhil; Shafir, Eldar (2012)


When we told an economist colleague that we were studying scarcity, he remarked, “There is already a science of scarcity. You might have heard of it. It’s called economics.”

Our approach to scarcity is different.

In economics, scarcity is ubiquitous. All of us have a limited amount of money; even the richest people cannot buy everything. But we suggest that while physical scarcity is ubiquitous, the feeling of scarcity is not. Imagine a day at work where your calendar is sprinkled with a few meetings and your to- do list is manageable. You spend the unscheduled time by lingering at lunch or at a meeting or calling a colleague to catch up.

Now, imagine another day at work where your calendar is chock- full of meetings. What little free time you have must be sunk into a project that is overdue. In both cases time was physically scarce. You had the same number of hours at work and you had more than enough activities to fill them. Yet in one case you were acutely aware of scarcity, of the finiteness of time; in the other it was a distant reality, if you felt it at all.

The feeling of scarcity is distinct from its physical reality. Scarcity is not just a physical constraint. It is also a mindset. When scarcity captures our attention, it changes how we think—whether it is at the level of milliseconds, hours, or days and weeks. By staying top of mind, it affects what we notice, how we weigh our choices, how we deliberate, and ultimately what we decide and how we behave.

When scarcity captures the mind, we become more attentive and efficient.

We can directly measure mental capacity or, as we call it, bandwidth.

We can measure fluid intelligence, a key resource that affects how we process information and make decisions.

We can measure executive control, a key resource that affects how impulsively we behave.

And we find that scarcity reduces all these components of bandwidth— it makes us less insightful, less forward- thinking, less controlled.

And the effects are large. Being poor, for example, reduces a person’s cognitive capacity more than going one full night without sleep.

It is not that the poor have less bandwidth as individuals. Rather, it is that the experience of poverty reduces anyone’s bandwidth.

When we think of the poor, we naturally think of a shortage of money. When we think of the busy, or the lonely, we think of a shortage of time, or of friends. But our results suggest that scarcity of all varieties also leads to a shortage of bandwidth. And because bandwidth affects all aspects of behavior, this shortage has consequences. We saw this with Sendhil and Shawn.