Pleasure describes the broad class of mental states that humans and other animals experience as positive, enjoyable, or worth seeking. It includes more specific mental states such as happiness, entertainment, enjoyment, ecstasy, and euphoria. The early psychological account of pleasure, the pleasure principle, describes it as a positive feedback mechanism, motivating the organism to recreate in the future the situation which it has just found pleasurable and to avoid situations that have caused pain in the past.
The experience of pleasure is subjective and different individuals will experience different kinds and amounts of pleasure in the same situation. Many pleasurable experiences are associated with satisfying basic biological drives, such as eating, exercise, hygiene, and sex. The appreciation of cultural artifacts and activities such as art, music, dancing, and literature is often pleasurable.
Based upon the incentive salience model of reward – the attractive and motivational property of a stimulus that induces approach behavior and consummatory behavior – an intrinsic reward has two components: a "wanting" or desire component which is reflected in approach behavior and a "liking" or pleasure component that is reflected in consummatory behavior. While all pleasurable stimuli are rewards, some rewards do not evoke pleasure (e.g. money).
Pleasure centers or "hedonic hotspots" are a set of brain structures within the reward system that are directly responsible for mediating the "liking" or pleasure component of an intrinsic reward, as opposed to brain structures that activate in correlation with or as a consequence of the perception of pleasure. Various compartments within the nucleus accumbens, ventral pallidum, and parabrachial nucleus have been identified as pleasure centers which respond to a variety of pleasurable stimuli. The orbitofrontal cortex and insular cortex likely contain hedonic hotspots as well. The anterior cingulate cortex, ventral tegmental area, and amygdala have also been observed to activate in functional neuroimaging studies in response to pleasurable stimuli, but these structures do not necessarily contain hedonic hotspots.
Pleasure is considered to be one of the core dimensions of emotion. It can be described as the positive evaluation that forms the basis for several more elaborate evaluations such as "agreeable" or "nice". As such, pleasure is an affect and not an emotion, as it forms one component of several different emotions. Pleasure is sometimes subdivided into fundamental pleasures that are closely related to survival (food, sex, and social belonging) and higher-order pleasures (e.g., viewing art and altruism). The clinical condition of being unable to experience pleasure from usually enjoyable activities is called anhedonia. An active aversion to obtaining pleasure is called hedonophobia.
Pleasure is often regarded as a bipolar construct, meaning that the two ends of the spectrum from pleasant to unpleasant are mutually exclusive. This view is e.g. inherent in the circumplex model of affect. Yet, some lines of research suggest that people do experience pleasant and unpleasant feelings at the same time, giving rise to so-called mixed feelings.
The degree to which something or someone is experienced as pleasurable not only depends on its objective attributes (appearance, sound, taste, texture, etc.), but on beliefs about its history, about the circumstances of its creation, about its rarity, fame, or price, and on other non-intrinsic attributes, such as the social status or identity it conveys. For example, a sweater that has been worn by a celebrity will be more desired than an otherwise identical sweater that has not, though considerably less so if it has been washed. Another example was when Grammy-winning, internationally acclaimed violinist Joshua Bell played in the Washington D.C. subway for 43 minutes, attracting little attention from the 1,097 people who passed by, and earning about $59 in tips. Paul Bloom describes these phenomena as arising from a form of essentialism.
Epicurus and his followers defined the highest pleasure as the absence of suffering and pleasure itself as "freedom from pain in the body and freedom from turmoil in the soul". According to Cicero (or rather his character Torquatus) Epicurus also believed that pleasure was the chief good and pain the chief evil.
In the 12th century Razi's "Treatise of the Self and the Spirit" (Kitab al Nafs Wa’l Ruh) analyzed different types of pleasure, sensuous and intellectual, and explained their relations with one another. He concludes that human needs and desires are endless, and "their satisfaction is by definition impossible."
Philosophies of pleasure
As a uniquely human experience
In the past, there has been debate as to whether pleasure is experienced by other animals rather than being an exclusive property of humankind; however, it is now known that animals do experience pleasure, as measured by objective behavioral and neural hedonic responses to pleasurable stimuli.