Opportunism is the practice of taking advantage of circumstances – with little regard for principles or with what the consequences are for others. Opportunist actions are expedient actions guided primarily by self-interested motives. The term can be applied to individual humans and living organisms, groups, organizations, styles, behaviors, and trends. Opportunism or "opportunistic behaviour" is an important concept in such fields of study as biology, transaction cost economics, game theory, ethics, psychology, sociology and politics. Opportunism is the conscious policy and practice of taking advantage of circumstances. Although in many societies opportunism often has a strong negative moral connotation, it may also be defined more neutrally as putting self-interest before other interests when there is an opportunity to do so, or flexibly adapting to changing circumstances to maximize self-interest (though usually in a way that negates some principle previously followed). Opportunism is sometimes defined as the ability to capitalize on the mistakes of others: to exploit opportunities created by the errors, weaknesses or distractions of opponents to one's own advantage. Taking a realistic or practical approach to a problem can involve "weak" forms of opportunism. For the sake of doing something that will work, or that successfully solves the problem, a previously agreed principle is knowingly compromised or disregarded - with the justification that alternative actions would, overall, have a worse effect. In choosing or seizing opportunities, human opportunism is most likely to occur where: People can make maximum gains at the least cost to themselves. Relevant internal or external controls on their behavior are absent. People are pressured to choose and act. Criticism of opportunism usually refers to a situation where beliefs and principles are tested or challenged. Human opportunism should not be confused with "seeking opportunities", or "making use of opportunities when they arise".