Individuals high on the absorption subscale, which measures a subjects experiences of concentration to the exclusion of awareness of other events, showed weaker cortisol responses.In general infantry and special forces soldiers, measures of depersonalization and derealization increased significantly after training that includes experiences of uncontrollable stress, semi-starvation, sleep deprivation, as well as lack of control over hygiene, movement, communications, and social interactions. Pharmacological and situational causes
Depersonalization has been described by some as a desirable state, particularly by those that have experienced it under the influence of mood-altering recreational drugs. It is an effect of dissociatives and psychedelics, as well as a possible side effect of caffeine, alcohol, amphetamine, cannabis, and antidepressants. It is a classic withdrawal symptom from many drugs.Benzodiazepine dependence, which can occur with long-term use of benzodiazepines, can induce chronic depersonalization symptomatology and perceptual disturbances in some people, even in those who are taking a stable daily dosage, and it can also become a protracted feature of the benzodiazepine withdrawal syndrome.Lieutenant Colonel Dave Grossman, in his book On Killing, suggests that military training artificially creates depersonalization in soldiers, suppressing empathy and making it easier for them to kill other human beings.Graham Reed (1974) claimed that depersonalization occurs in relation to the experience of falling in love. Depersonalization as a psychobiological mechanism
Depersonalization is a classic response to acute trauma, and may be highly prevalent in individuals involved in different traumatic situations including motor vehicle accident, and imprisonment.Psychologically depersonalization can, just like dissociation in general, be considered a type of coping mechanism.
Insects of the superorder Endopterygota, also known as Holometabola, such as butterflies, ants, bees, beetles, fleas, flies, moths, and wasps, undergo holometabolism—complete metamorphism in four stages—from (1) embryo (ovum, egg), to (2) larva (such as grub, caterpillar), then (3) pupa (such as the chrysalis), and finally (4) the imago. In the common ABO blood group system, there are four blood types (A, B, O, AB). Humans have four canines and four wisdom teeth. The cows stomach is divided in four digestive compartments: reticulum, rumen, omasum and abomasum. In chemistry
Valency of carbon (that is basis of life on the Earth) is four. Also because of its tetrahedral crystal bond structure, diamond (one of the natural allotropes of carbon) is the hardest known naturally occurring material. It is also the valence of silicon, whose compounds form the majority of the mass of the Earths crust. The atomic number of beryllium
There are four basic states of matter: solid, liquid, gas, and plasma. In physics
Special relativity and general relativity treat nature as four-dimensional: 3D regular space and one-dimensional time are treated together and called spacetime. Also, any event E has a light cone composed of four zones of possible communication and cause and effect (outside the light cone is strictly incommunicado). There are four fundamental forces (electromagnetism, gravitation, the weak nuclear force, and the strong nuclear force). In statistical mechanics, the four functions inequality is an inequality for four functions on a finite distributive lattice.