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@MarkWebberFan
I think those "others" include factors which are region-specific. The source you mentioned is using a useful metric, enough to know the general trend of racism but not the specific reasons for it. I think one of the specific reasons why an arab would act racist towards a non-arab has more to do with islam and its close ties to the arab culture. For example, Qatar had provoked the international community about its abusive treatment of muslim labor workers from non-arab countries. I think these factors are ultimately region-specific. I don't know much about the west's racial tolerance. I do maintain that experience has more influence on any kind of racism.
True. I didn't provide a great example, due to the confounding variables you listed.
I'll provide a better argument now to support the idea that racial disliking/hatred of other races is, at least, somewhat innate.
My argument in short: Research shows that people who like others who have closer similarity to themselves. Furthermore, as a trait becomes more heritable, the more important it becomes for friends/spouses/social groups etc. Therefore, people prefer the company of those people who are genetically more similar to them.
We consistently see that friends and spouses are more similar in many ways. Berscheid and Hatfield's (1969) performed social experiments with people to find that people are "more likely to desire a relationship with those that were seen to share attitudes. They found that the more important a shared attitude, the higher the attraction rating. For example, two people who both prefer the same type of toothpaste were not as attracted to each other as two people who shared the same religious beliefs." Similarity-Attraction Paradigm: Definition & Criticisms | Study.com
Bryne (1971) later steelmans this idea with his work, which unfortunately is behind a paywall The Attraction Paradigm - Donn Erwin Byrne - Google Books . However, we get glimpses at his work with a key result from one of his earlier works: the attraction paradigm byrne - Bing images , and a defense in 1986 of his work against criticism: (PDF) The Attraction Hypothesis. Do Similar Attitudes Affect Anything? (researchgate.net) .
Specifically for spouses, Luo and Klohen (2005) showed that newlyweds had substantial similarity in attitudes (although, interestingly, only a "little" on personality). Moreover, this similarity mattered greatly in more important things like religion (which echoes Bercheid and Hatfield's claim) psp-882304.pdf (apa.org) . Caspi and Herbener (1990) also found that, "Consistent with other research, the results point to homogamy as a basic norm in marriage," but this study also seems to be locked behind a paywall Continuity and change: Assortative marriage and the consistency of personality in adulthood. - PsycNET (apa.org) .
We can attribute at least some of these preferences for beliefs to genes, and then argue that people like other people with similar genes to them.
Christakis and Fowler (2013) produced a jargon-heavy, somewhat mathematically dense read (at least I found it difficult to read) that says: "More than any other species, humans form social ties to individuals who are neither
kin nor mates, and these ties tend to be with similar people. Here, we show that this
similarity extends to genotypes." Microsoft Word - FANS v3.4.docx (arxiv.org) . It should be noted that this study suggests genomic homophily only correlates to likeability (i.e. isn't causation). A specific example involves the fact that "friends tend to have genotypes that yield similar senses of smell", in that in "the 174 most homophilic genes (top 1% [of what they tested]), olfactory transduction pathway [was] significantly overrepresented". In plain English: your sense of smell is quite important in the friends you select (something I would have disagreed with before reading this paper).
As for spouses being genetically similar, we have Domingue et al (2014) which found that "spouses are more genetically similar than two individuals chose at random" Genetic and educational assortative mating among US adults | PNAS . It should be noted that this effect is only one-third the magnitude of "educational similarity", which shows that genomic similarity absolutely does not account for the only reason why people like each other (at least according to all this research).
We can then show that human races are genetically different, and therefore conclude that, at best, people who are more genetically different won't like each other as much (i.e. becoming indifferent), and may be disliking or hateful of those dissimilar to themselves, depending on how important the difference is.
So, people of the same race are more likely to be genetically similar to people of differing races, according to Witherspoon et al 2007. Moreover, if enough of the genome is measured, the likelihood that people of the same race will be genetically similar, when compared to people of a different race, approaches 100% (but doesn't reach it) genet67355 351..359 (nih.gov) .
