Definitions:

Many definitions of power have been proposed. These include:

1. The ability to limit the choices of another.
2. Carrying out one's will despite resistance from others.
3. The use of constraint (physical or psychological) in pursuit of one's goal.
4. The desire for influence; imposing your will on others or the environment

However, the definition that seems to be most precise, and provides the most insight is:

• An asymmetrical dyadic relationship.

It is instructive to recognize that power is an attribute of the relationship and not of the person. To better understand this, I like to imagine a powerful and generally feared boss standing in a long line at the state motor vehicle registration agency. While at work this person is the boss but here he or she is just as powerless as anyone else, having to wait a very long time to talk to a junior level clerk to get the car registered. Here the asymmetry is clear, the boss waits while the clerk takes their good old time and holds all the cards. In this relationship, the boss has submitted to the clerk.

The asymmetries of power may not be expressed unless goals are in conflict. In other words, a gentle giant is not likely to harm you unless you provoke him into a conflict.

Power can be exercised from these three basic postures:

• Dominance—The ability to inflict harm, also know as aggressive coercion, or
• Status—The ability to provide help, also know as leverage.
• Influence—altering people's beliefs.

The first two power bases are the proverbial "carrot and stick". The third is an implicit and pervasive method used to alter people's behavior.

Power can be characterized, measured, and compared based in the following four characteristics:

1. Base is the source of power, such as fighting ability or control over sexual access, favors, affiliation, or other sources of leverage. The base is some form of either dominance or status.
2. Means refers to the instruments of power, such as threat or reward, and it is the way the relationship is negotiated,
3. Amount refers to the magnitude of power, how it may vary with the context of a situation, (e.g. within a territory) and how often it is exercised,
4. Scope refers to the range of power and it describes the types of behaviors the powerful agent "A" can evoke from the subordinate "B"

These characteristics provide a means to measure and describe why, how, when, and to what extent power occurs.

The outcome of a competition is determined by dominance, leverage (status), and motivation. Power dynamics only enter a contest when the goals of the participants conflict. When resources are abundant free and peaceful access is likely and competition is unlikely. If scarce resources are concentrated or positioned so they can be defended, then conflict is likely, and the resources are distributed according to the power of those contending for them. If resources are limited but not defensible, then tolerance and sharing are more likely than conflict.

Power can be aggression-based (known as aggressive coercion or dominance) or dependence-based (i.e. based on status or leverage). If person "B" depends on person "A" for resources, knowledge, affection, praise, approval, companionship, rewards, or anything else, then "A" has dependence-based power over "B". The amount of power "A" has over "B" in this relationship is related to how much "B" values the resources controlled by "A", and the availability of substitutes or alternative sources.

Powerful Personalities

Personality is an important instrument of power. Although power is defined in terms of a relationship, we consistently regard some people as powerful individuals and others as weak. Personal attributes that contribute to powerful personalities include physical size and strength, especially including tall men, because strength supports the association of power with dominance. Increasingly, mental resources including precision, acuity, charm, apparent honesty, humor, and solemnity are important. Communicating thoughts lucidly and eloquently contributes to the powerful personality. It is also important to convey a supreme certainty in your own beliefs, including the ability to assert the unknown with the greatest conviction. Rituals, including meetings, audiences, and applause also enhance the powerful image.

Keeping cool while others are demanding, dependent, or chaotic presents a powerful image. It sends the message "they need me more than I need them, I am self-reliant and in control." Keeping calm in the face of another's anger maintains control in a conflict. Going a step further, demonstrating indifference towards others shames them while it distinguishes and distances the self-reliant and powerful personality. Indifference creates a mixture of fear an awe that enhances the powerful personality.

Authority and Power

The English language use of the word "authority" has two very different meanings. One meaning describes power—such as the right to control, command, or determine—and the other described expertise—an accepted source of information. People identify authority with legitimacy; authority exists when people voluntarily obey those with positional power, such as government leaders, officers of the law and courts, and superiors within an organizational hierarchy. Authority is a belief in legitimacy measured by voluntary compliance. 

A recognized authority can obtain power from one or more of the three basic postures of dominance, status, and influence:

• Positional power often legitimizes the use of coercive sanctions. For example, your boss can give you unfavorable assignments, fire you, or refuse to give you a rise or promotion. Police officers are authorized to make arrests. This provides the authority with power based on dominance.
• A true expert derives authority from the unique information, skill, or talent they command. Here the authority has power based on status.
• An influential authority gains voluntary compliance.

A fear of authority arises when we are attracted to strong figures who we do not believe are legitimate.

Quotations

• Of the infinite desires of man, the chief are the desires for power and glory ~ Bertrand Russell
• The love of power is the love of ourselves ~ William Hazlitt
• The injustice of society is that the subordinate must make sense of what power is ~ Hegel.
• Liberty finally exists when the recognition I give you does not subtract something from myself ~ Richard Sennett

References:

Beyond Dominance: the importance of leverage, Rebecca J. Lewis, The Quarterly Review of Biology, volume 77 (2002), pages 149–164. Published by the University of Chicago Press

Chapais B. 1991. Primates and the origins of aggression, power, and politics among humans. Pages 190-218 in Understanding Behavior: What Primate Studies Tell Us About Human Behavior, edited by J D Loy and C B Peters. Oxford: Oxford University Press.

The Power Principle: Influence with Honor, by Blaine Lee

The Empowered Manager: Positive Political Skills at Work, by Peter Block

The 48 Laws of Power, by Robert Greene

The Anatomy of Power, by John Kenneth Galbraith

Authority, by Richard Sennett

Demonic Males: Apes and the Origins of Human Violence, by Dale Peterson, Richard Wrangham

The Selfish Gene, by Richard Dawkins