The idea of normal behavior, normal belief, and normal ways of conducting oneself through life, comes from several sources. For individuals, a regular and dependable set of experiences with cause and effect can lead to behavior that is geared toward actions which lead to positive results, which then evolve int individual norms.
For groups, externally imposed or agreed upon standards for behavior that is one thing when a person is alone, but another when in a group, can become defined as "normal" or "deviant" based on the level of agreement and shared values of the group. Some behaviors are considered deviant whether or not someone else is around.
In all societies, the standards of deviance and norm can become quite complicated, variable, convoluted, and crazy.
One charismatic religious or political leader can convince millions of people that any number of behaviors are to be reclassified as either deviant or normal. Before the life of Jesus, it was the social norm to want to just kill a person who was an enemy, or who violated a religious law. Jesus taught that some laws were ridiculous, and that it is better to forgive and to not judge at all. Jesus was considered a deviant during his lifetime. Today his teachings are considered to be the norm in religious teaching and thought for billions of people.
It is almost universally deviant to consider eating human flesh, or resorting to cannibalism. Yet a common Christian ritual involves consuming sanctified substitutes for the blood and flesh of Christ.
In the past, a ruler's power to define and enforce a norm determined a nation's norms. Nothing that the leader could do could be judged as deviant because the leader dictated what was deviance or norm.
Now, political deviance is clearly manifest when the leader violates externally defined unlawful authority to absolve him or herself as well as any associates of any wrongdoing. Pogroms, torture, assassination, genocide, environmental abuses, purges, and mass destruction are considered to be deviant political activities which go against the principles of most of today's world powers.
It was once considered highly deviant to introduce dead viruses and bacilli into the bloodstreams of healthy individuals. Then, such activity became the norm, and was enforced by law. Now, the norm is being challenged as the side effects of vaccinations are being weighed against the value of disease prevention that vaccinations offer.
It used to be the norm to dress to the nines for church on Sunday. Today, sweat suits, ball caps, jeans, and any comfortable clothes may be worn to religious services in many churches.
The patriotic norms of nations used to involve at least standing and remaining quiet while national anthems are played at sports events. Now, the patriotic rituals, while honored, are far more casual affairs.
Same sex relationships in much of the developed world are transitioning from a status of being completely deviant, into a status of being socially tolerable, even though there are great divisions in and between the many societies in the world.
Deviancy in religion is leading to the expanded enforcement of Sharia Law, which calls for horrific acts of murder, mutilation, torture, enslavement, and oppression of homosexuals, women and girls.
Racial segregation and exclusion, once considered an acceptable norm is now considered deviancy, when basic civil rights are denied. But Sunday is joked about as the most segregated day of the week in religious circles. Voluntary segregation in housing and other areas is considered the norm, depending on the religion, region, country, and other national ideas about who is in one group and who is in another. Strict segregation goes in in Israel, where many Secular and Orthodox Jews refuse to intermingle any more than is necessary.
As a result, segregation inclusion and exclusion, whatever the case, remains both a norm and a deviancy, depending on it's nature, its effect on human rights, and it's place in the voluntary, national or international sense of what is right or wrong.