All known life-forms exhibit the Nietzschean "Will to Power" (also known as the "Will to Live" and/or the "Survival Instinct/Reproductive Urge").
Individual life-forms cannot survive without at least the following two conditions obtaining:
(A) Destroying and consuming (in a sort of cannibalistic sense) other life forms as food (part of the struggle or competition for survival), and
(B) Reproducing their kind. This can be described as passing on their accumulated genetic heritage, which is each species' own unique recorded 'advice' (as it were) on how best to survive in the 'jungle'. In addition to merely reproducing, they must also do their best to see to it that more members of their family, tribe, nation, or species survive and reproduce than members of other families, tribes, nations, or species. This last is really only another adjunct or description of the above destructive impulse; that is, we may basically say that individual life-forms must destroy other life-forms in order to survive, whether as individual or species. This is the so-called "Law of the Jungle": kill or be killed.
Human beings, though (and this is part of what sets us apart from the other animals)--because of their more logical, reasoning, self-intuitive or reflective minds, and their capacity for highly-developed and highly-expressed emotion of altruism--are capable of significantly delaying and somewhat negating the above-described instinctive bio-survival/reproductive urge, and its attendant destructive impulse. Human beings, we may say, are thus not usually as dominated by this urge and its consequences as are most other species.
However, human beings are still somewhat under the influence of this destructive, self-perpetuating urge, to the degree that we are still animalian and still dominated by our animal genetic heritage (including instincts): we human beings still often seek to harm, persecute, or destroy minorities, which we may define as any individual or sub-group which is significantly different from the majority of the population of any given locale, and which thus seems to pose a threat to the individual/species bio-survival of the societal 'majority'.
This xenophobia and persecution would thus be perfectly explainable in terms of humankind's animal genetic heritage, instincts, and responses to the stimuli presented by other, significantly different people, but it would seem to be a stumbling-block, a primitive animal throwback, standing in the way of humankind's evident future evolutionary path--that is, toward greater use of reason, greater display of altruism, and less dependence upon violent, irrational, 'negative' animal emotion and instinct.
We would, of course, wish to see our species advance in this direction, and decry these recurrent primitive throwbacks of hatred, fear, and persecution. Why, we may (with justification) ask, does this bio-survival/reproductive urge (and its corollaries) still frequently cause human beings to seek to harm or destroy others? Why do reason and altruism (assumed to be growing, developing evolutionary traits native to human beings) seem to periodically fail?
The answers lie somewhere in the following area, I believe:
We may say that this persecution occurs because of the following:
One rather simple explanation is in terms of pure xenophobia: we may say that on a very basic , organic level--the level of simple organism versus organism--whatever is perceived as "not me" is therefore seen as something alien and foreign--something to be always cautiously on guard against as a potential threat to bio-survival; something, therefore, to be overcome and vanquished as a potential threat. This will all become much clearer if we picture ourselves on the level of the paramecium, for example. This very primitive and ancient instinctual urge or perception is offset somewhat--but never completely negated--by the additional survival instinct of altruism, that is, the urge toward nurturing our offspring as insurance toward the survival of the personal/tribal/species gene pool.
Another way of stating this would be to say that misunderstanding, fear and hatred are negative and undesirable primitive animal-like emotional reactions to perceived threats to the gene pool, and/or the bio-survival/reproductive urge, and to perceived violations of the cultural 'taboos' which are nominally structured to protect the same, and that
This misunderstanding, fear, and hatred can develop between individuals, or between individuals and groups, or between a 'majority' grouping and a minority or minorities, and that
These undesirable 'negative' emotional reactions occur--in individuals and in entire societies--because reason and altruism fail to counteract or control them.
WHY? Reason and Altruism (I believe) fail to control these undesirable emotional reactions usually because life and survival are still so often so precarious and uncertain for most human beings (as indeed for all other life-forms). In instances of inadequate or failed communication (which can lead to distrust and misunderstanding), and/or instances of unusually strong perceived threats to bio-survival, the gene pool, or 'taboos', most human beings will (naturally and understandably) be unable to interpose with reason and altruism (though this does not excuse them), and will instead react with hatred, fear and violence toward anything or anyone which seems to threaten "my life," "my offspring," "my family," "my tribe," etc., or any other aspect of the comfortable 'status quo' system which supports these ends, and provides most human beings with (necessary, we must remind ourselves) existential security, stability, and comfort. (And this definitely includes 'religious' structures.)
Most average human beings will continue to react in this manner until one or both of the following two conditions obtain:
(A) A substantial majority of individual human beings becomes sufficiently intelligent and knowledgable that reason and altruism must more frequently dominate over animal emotion and instinct (and this is of course an evolutionary process, as I have already said), and
(B) That life and survival are no longer precarious and uncertain for most human beings, and that they therefore may become more complacent and tolerant from lack of worry and extreme.
T.J.White, August, 1994