Taboo on the dead

The taboo on the dead includes the taboo against touching of the dead, those surrounding them and anything associated with the dead.
The taboo against naming the dead.
A taboo against naming the dead is a kind of word taboo whereby the name of a recently deceased person, and any other words similar to it in sound, may not be uttered. It is observed by peoples from all over the world, including Australia, Siberia, Southern India, the Sahara, Subsaharan Africa, and the Americas.
Examples.
After a Yolngu man named Bitjingu died, the word "bithiwul" "no; nothing" was avoided. In its place, a synonym or a loanword from another language would be used for a certain period, after which the original word could be used again; but in some cases the replacement word would continue to be used.
In some Australian Aboriginal cultural practices, the dead are not referred to by their name directly as a mark of respect. In Pitjantjatjara, for instance, it is common to refer to a recently deceased person as 'kunmanara', which means "what's his name". Often, the person's last name can still be used. The avoidance period may last anywhere from 12 months to several years, depending on how important or famous the person was. The person can still be referred to in a roundabout way, such as "that old lady" or by generic skin type but not by first name. Other reasons may include not making mockery of that person and keeping respect with regard to them. For this reason, the names of many notable Aboriginal people were only recorded by Westerners and may have been incorrectly transliterated.
Effects on language.
R. M. W. Dixon has suggested, in reference to Australian Aboriginal languages, that the substitution of loanwords for tabooed words results in significant vocabulary replacement, hindering the application of the comparative method. Other linguists find the effects of the taboo on vocabulary replacement to be insignificant.
Goddard (1979) also suggests upon finding evidence of name-taboos of the deceased in Tonkawa similar to Australian languages, the languages of southeast North America may have resisted classification into language families so far due in part to vocabulary replacement (in addition to their already sparse documentation).
Taboo on contact with the dead.
In Judaism, contact with a corpse causes a person to become ritually impure, and thus unable to enter the Temple until purified using the ashes of the red heifer. This defilement can be caused not only by physical contact with the dead, but also by indirect contact (e.g. contact with one who touched a body) or by entering a building or room containing a corpse. As the red heifer does not currently exist, all Jews are considered by Halakha to be ritually impure regarding the Temple Mount. Kohanim (Jewish priests) are further restricted, being forbidden from intentionally coming into contact with the dead or from walking too closely to a grave. Exceptions are made for a Kohen's seven closest relatives that have died (father, mother, brother, unmarried sister, son, daughter, or wife).
Origins and causes.
Sigmund Freud explains that the fundamental reason for the existence of such taboos is the fear of the presence or of the return of the dead person's ghost. It is exactly this fear that leads to a great number of ceremonies aimed at keeping the ghost at a distance or driving it off. In many cases the taboo remains intact until the body of the dead has completely decayed.
Psychologist Wilhelm Wundt associates the taboo with a fear that the dead man's soul has become a demon. Moreover, many cases show a hostility toward the dead and their representation as malevolent figures. Edward Westermarck notes that "Death is commonly regarded as the gravest of all misfortunes; hence the dead are believed to be exceedingly dissatisfied with their fate [...] such a death naturally tends to make the soul revengeful and ill-tempered. It is envious of the living and is longing for the company of its old friend."