Laziness (also called indolence) is a disinclination to activity or exertion despite having the ability to do so. It is often used as a pejorative; related terms for a person seen to be lazy include couch potato, slacker, and bludger.
Despite Sigmund Freud's discussion of the pleasure principle, Leonard Carmichael notes that "laziness is not a word that appears in the table of contents of most technical books on psychology... It is a guilty secret of modern psychology that more is understood about the motivation of thirsty rats and hungry pecking pigeons as they press levers or hit targets than is known about the way in which poets make themselves write poems or scientists force themselves into the laboratory when the good golfing days of spring arrive." A 1931 survey found that high school students were more likely to attribute their failing performance to laziness, while teachers ranked "lack of ability" as the major cause, with laziness coming in second. Laziness is not to be confused with avolition, a negative symptom of certain mental health issues such as depression, ADHD, sleep disorders, and schizophrenia.
From 1909 to 1915, the Rockefeller Sanitary Commission for the Eradication of Hookworm Disease sought to eradicate hookworm infestation from 11 southern U.S. states. Hookworms were popularly known as "the germ of laziness" because they produced listlessness and weakness in the people they infested. Hookworms infested 40 percent of southerners and were identified in the North as the cause of the South's alleged backwardness.
It was alleged that indolence was the reason for backward conditions in Indonesia, such as the failure to implement Green Revolution agricultural methods. But a counter-argument is that the Indonesians, living very precariously, sought to play it safe by not risking a failed crop, given that not all experiments introduced by outsiders had been successful.
One of the Catholic seven deadly sins is sloth, which is often defined as spiritual and/or physical apathy or laziness. Sloth is discouraged in (Hebrews 6:12), 2 Thessalonians, and associated with wickedness in one of the parables of Jesus in the Gospel of Matthew (Matthew 25:26). In the Wisdom books of Proverbs and Ecclesiastes, it is stated that laziness can lead to poverty (Proverbs 10:4, Ecclesiastes 10:18). According to Peter Binsfeld's Binsfeld's Classification of Demons, Belphegor is thought to be its chief demon.
The Arabic term used in the Quran for laziness, inactivity and sluggishness is كَسَل (kasal). The opposite of laziness is Jihad al-Nafs, i.e. the struggle against the self, against one’s own ego. Among the five pillars of Islam, praying five times a day and fasting during Ramaḍān are part of actions against laziness.
In Buddhism, the term kausīdya is commonly translated as "laziness" or "spiritual sloth". Kausīdya is defined as clinging to unwholesome activities such as lying down and stretching out, procrastinating, and not being enthusiastic about or engaging in virtuous activity.
Economists have differing views of laziness. Frédéric Bastiat argues that idleness is the result of people focusing on the pleasant immediate effects of their actions rather than potentially negative long-term consequences. Others note that humans seem to have a tendency to seek after leisure. Hal Cranmer writes, "For all these arguments against laziness, it is amazing we work so hard to achieve it. Even those hard-working Puritans were willing to break their backs every day in exchange for an eternity of lying around on a cloud and playing the harp. Every industry is trying to do its part to give its customers more leisure time." Ludwig von Mises writes, "The expenditure of labor is deemed painful. Not to work is considered a state of affairs more satisfactory than working. Leisure is, other things being equal, preferred to travail (work). People work only when they value the return of labor higher than the decrease in satisfaction brought about by the curtailment of leisure. To work involves disutility."
It is common for animals (even those like hummingbirds that have high energy needs) to forage for food until satiated, and then spend most of their time doing nothing, or at least nothing in particular. They seek to "satisfice" their needs rather than obtaining an optimal diet or habitat. Even diurnal animals, which have a limited amount of daylight in which to accomplish their tasks, follow this pattern. Social activity comes in a distant third to eating and resting for foraging animals. When more time must be spent foraging, animals are more likely to sacrifice time spent on aggressive behavior than time spent resting. Extremely efficient predators have more free time and thus often appear more lazy than relatively inept predators that have little free time. Beetles likewise seem to forage lazily due to a lack of foraging competitors. On the other hand, some animals, such as pigeons and rats, seem to prefer to respond for food rather than eat equally available "free food" in some conditions.