diversity is strength

Putnam's study: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-9477.2007.00176.x

Good Fences: http://necsi.edu/research/social/scienceofpeace.pdf

Self-identification study: https://www.ncbi.nlm.nih.gov/pubmed/15625622

Everything else:

More diverse neighborhoods have lower social cohesion.

http://www.citylab.com/housing/2013/11/paradox-diverse-communities/7614/

Diversity increases psychotic experiences.

Diversity increases social adversity.

A 10% increase in diversity doubles the chance of psychotic episodes.

http://bjp.rcpsych.org/content/201/4/282.abstract?etoc

Diversity reduces voter registration, political efficacy, charity, and number of friendships.

Ethnic diversity reduces happiness and quality of life.

http://onlinelibrary.wiley.com/doi/10.1111/j.1467-9477.2007.00176.x/abstract;jsessionid=279C92A7EB0946BBA63D62937FC832A9.f04t03

Diversity reduces trust, civic participation, and civic health.

http://www.boston.com/news/globe/ideas/articles/2007/08/05/the_downside_of_diversity/?page=full

Ethnocentrism is rational, biological, and genetic in origin.

http://www.pnas.org/content/108/4/1262.abstract

Ethnic diversity harms health for hispanics and blacks.

http://ajph.aphapublications.org/doi/abs/10.2105/AJPH.2012.300787

Babies demostrate ethnocentrism before exposure to non-whites.

http://onlinelibrary.wiley.com/doi/10.1111/j.1467-7687.2012.01138.x/full

Ethnocentrism is universal and likely evolved in origin.

http://www-personal.umich.edu/~axe/research/AxHamm_Ethno.pdf

Diversity in American cities correlates with segregation.

http://fivethirtyeight.com/features/the-most-diverse-cities-are-often-the-most-segregated/

Races are extended families. Ethnocentrism is genetically rational.

http://www.amazon.com/The-Ethnic-Phenomenon-Pierre-Berghe/dp/0275927091

It is evolutionarily rational to be friends with someone genetically similar to you.

http://www.livescience.com/46791-friends-share-genes.html

Racism and nationalism are rational and evolutionary advantageous strategies.

http://jasss.soc.surrey.ac.uk/16/3/7.html

Homogeneous polities have less crime, less civil war, and more altruism.

http://www.theindependentaustralian.com.au/node/57

States with little diversity have more democracy, less corruption, and less inequality.

http://www.theindependentaustralian.com.au/node/57

There is extensive evidence people prefer others who are genetically similar.

http://psychology.uwo.ca/faculty/rushtonpdfs/n&n_2005-1.pdf

Our analysis shows that peace does not depend on integrated coexistence, but rather on well defined topographical and political boundaries separating groups

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0095660

The more integrated a neighborhood is, the less socially cohesive it becomes, and vice versa.

http://msutoday.msu.edu/news/2013/study-asks-is-a-better-world-possible/

The more ethnically diverse the people we live around, the less we trust them.

http://macaulay.cuny.edu/eportfolios/benediktsson2013/files/2013/04/Putnam.pdf

Ethnocentrism, often thought to rely on complex social cognition and learning, may have arisen through biological evolution.

http://jasss.soc.surrey.ac.uk/16/3/7.html

Diversity experiments in Germany end in disaster

http://www.spiegel.de/international/germany-s-immigrants-integration-in-theory-alienation-in-practice-a-433006.html

Immigrants in Norway are a net loss to the economy


http://www.emnbelgium.be/publication/report-norwegian-welfare-and-migration-committee

Immigrants in Sweden are a net loss to the economy

http://www.amid.dk/pub/papers/AMID_48-2006_Jan_Ekberg.pdf

Denmark saved billions by restricting immigration:

http://www.spiegel.de/international/europe/putting-a-price-on-foreigners-strict-immigration-laws-save-denmark-billions-a-759716.html

http://www.telegraph.co.uk/news/worldnews/europe/denmark/8492822/Denmarks-immigration-laws-save-country-6-billion.html

Increases in diversity correlate with problems worldwide, and the downsides of diversity effect everyone, it’s a universal human problem:

http://www.theaustralian.com.au/higher-education/the-downside-of-difference/story-e6frgcjx-1111112914289

More diversity in police departments correlates with more abuse, poorer performance and less trust:

http://www.mediafire.com/?1fe8x0egftpbp6f

Decreased community spirit, decreased altruism, and depressed social capital, less ethical behavior, more crime, fear, isolation and depression:

http://www.city-journal.org/html/eon2007-06-25jl.html

Increasing social pluralism (diversity) is correlated with increased chance of collective violence-http://docdro.id/D9GRWG7

Using data from Copenhagen school registers, researchers found that native Danes opt out of public schools when the immigrant population concentration hits 35% or more-https://web.archive.org/web/20170216222016/http://emilkirkegaard.dk/en/wp-content/uploads/School-Choice-Universal-Vouchers-and-Native-Flight-from-Local-Schools.pdf

UK immigrants segregate into their own ethnically homogenous communities-https://web.archive.org/web/20180627132302/https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/575975/The_Casey_Review_Executive_Summary.pdf

Increases in immigrant density at the school level triggered an important native flight from tuition-free, public schools toward private ones-

https://www.sciencedirect.com/science/article/abs/pii/S0927537118300010

http://docdro.id/c1ahKvP

Globalization and the internet are increasing the proximity of human diversity and consequently increasing mutual animosity as well. “The scholars traced the phenomenon to what they called ‘environmental spoiling.’ The nearer we get to others, the harder it becomes to avoid evidence of their irritating habits. Proximity makes differences stand out.”

https://www.bostonglobe.com/ideas/2017/04/21/how-technology-created-global-village-and-put-each-other-throats/pu7MyoAkdyVComb9aKyu6K/story.html

Data from the National Longitudinal Study of Adolescent Health showed that multi ethnic diversity decreases happiness among all groups, and most markedly for the downscale and economically dispossessed

https://www.researchgate.net/publication/283881736_Happiness_in_modern_society_Why_intelligence_and_ethnic_composition_matter

Analysis of publicly available data and social science research finds that smaller, homogeneous cities have more social capital than larger, diverse cities-https://archive.is/kXy0r

Austrailian Study: “Our results provide at least partial support for Putnam's thesis.”-http://docdro.id/cjUbT5J

“Diverse schools do not make White British students more inclusive in their attitudes on immigrants”…”Diverse schools reduce trust in people of one’s own age”-http://docdro.id/imTlsUI

“Increasing diversity undermines attitudes among stayers. Individuals who move from a diverse to a homogeneous community report improved attitudes. However, there is no effect among individuals who move from a homogeneous to a diverse community.”-http://docdro.id/v5lNemf

“trust is an integral part of a tight syndrome of social, political and economic conditions,”…“High trust countries are characterized by ethnic homogeneity, Protestant religious traditions, good government, wealth (gross domestic product per capita), and income equality,”-http://docdro.id/6KZPqAA

A 2010 study found that higher ethnic heterogeneity in country was associated with lower tax morale

https://web.archive.org/web/20180526015948/https://www.utdallas.edu/~xxl068000/TaxMorale.pdf

A 2007 study found that higher ethnic heterogeneity in a country was associated with a larger "informal economy"-http://docdro.id/FqKhPZG

A 2017 study found that higher ethnic heterogeneity in US states was associated with less public spending on higher education-http://docdro.id/4tbG9Fq

A 2010 study found that countries with "moderate" levels of ethnic diversity had the best scores on the "Environmental Performance Index" and that increasing ethnic diversity beyond this was associated worsening environmental performance-http://docdro.id/pl6Febl

A study has found that an increase in “diversity” makes existing residents of a area feel unhappier and more socially isolated, while those leaving for more homogenous areas populated by their own ethic group often get happier-http://docdro.id/SihIqJb
http://docdro.id/SihIqJb

A 2012 study in the UK found that the risk of psychosis increased when a person lived in an area with a lower percentage of people from the same ethnicity-http://docdro.id/8QUybVx

Racial segregation persists in the U.S. housing market – even in cities that take pride in diversity-https://dailym.ai/2IHnIQR

A 2011 study in Canada found that higher ethnic heterogeneity reduced the size of individual donations to private charities-http://docdro.id/h8NqbTq

An overview of different studies published in 2003 stated that higher ethnic heterogeneity in an area is associated with negative effects regarding many variables, such as participation in organizations, volunteer activity, census response rate, and voting-http:

There is more bros

Ethnic Identity Gives Teens Daily Happiness Boost-https://archive.fo/usb69

Married couples have more DNA in common than random pairs of people-https://lat.ms/2y5A5Bd

Babies just 15 months old show racial bias when picking playmates-https://dailym.ai/2y2aitP

Oxytocin promotes human ethnocentrism-http://docdro.id/vTMWWqi

We found that everybody reported empathy toward the Hurricane Katrina victims," said Joan Y. Chiao, assistant professor of psychology and author of the study. "But African-Americans additionally showed greater empathic response to other African-Americans in emotional pain."-https://archive.li/JZ1on
The neurotransmitter oxytocin "makes people more co-operative, benevolent, loyal, generous and trusting of others. It is involved in the parent-child bond - new mothers and fathers have raised levels of oxytocin. Production also increases when people hug and when they have sex and, recent research suggests, when they receive psychological warmth." However, oxytocin has been alleged to "foster racism."-https://archive.li/CcQuL

Oxytocin promotes human ethnocentrism-https://archive.li/2bm3

Dutch Diversity Study Shows That Diversity Is Bad for Us

The Scientific Council for Government Policy (in Dutch: Wetenschappelijke Raad voor het Regeringsbeleid, WRR) released a scientific report this week, which shows that ethnic diversity negatively impacts social cohesion.

Full report (in Dutch) here:

https://www.wrr.nl/publicaties/verkenningen/2018/05/29/de-nieuwe-verscheidenheid

Translated from the full report (page 87):

Our analysis shows that, when a neighbourhood becomes more diverse, it becomes less socially cohesive. This result is significant. Social-economic factors have been taken into account. Although the social-economic status of a neighbourhood impacts cohesion, the impact of diversity on social cohesion IS LARGER THAN THE IMPACT OF SOCIAL ECONOMIC STATUS.

https://www.dutchnews.nl/news/2018/05/the-dutch-are-becoming-more-diverse-one-in-five-have-at-least-one-foreign-parent/

English news article which, safe for one small paragraph, ignores the negative impact of ethnic diversity.

https://www.nrc.nl/nieuws/2018/05/29/het-gaat-niet-meer-alleen-over-turken-en-marokkanen-a1604700

Dutch newspaper article, also downplaying hard.

https://en.wikipedia.org/wiki/Scientific_Council_for_Government_Policy

Here's a list with studies that support the idea that diversity in itself is a negative, and not only racial diversity:

https://heartiste.wordpress.com/diversity-proximity-war-the-reference-list/

diversity + proximity = war is the formula that captures the idea in general.

I'll list some its points:

– Social trust is negatively affected by ethnic diversity, case study in Denmark from 1979 to the present. Link.

– Ethnic homogeneity and Protestant traditions positively impact individual and societal levels of social trust. Link.

– “In longitudinal perspective, [across European regions], an increase in immigration is related to a decrease in social trust.” Link.

– Immigration undermines the moral imperative of those who most favor welfare benefits for the neediest. Link.

– The negative effect of community diversity on social cohesion is likely causal. Link.

– In Switzerland, social peace between diverse factions isn’t maintained by integrated coexistence, but rather by strong topographic and political borders that separate groups and allow them autonomy. Link.

– “Our analysis supports the hypothesis that violence between groups can be inhibited by both physical and political boundaries.” Link.

– Diversity hinders between-group cooperation at both the one-on-one and group levels. Link.

– The best chance for peace in Syria is better borders (intrastate or through the creation of new states) “suited to current geocultural regions”, and tribal autonomy. Link.

– Using data from US states, study finds a negative relationship between ethnic polarization and trust. Link.

– Diversity is associated with more White support for nationalist parties, except at the local level where large immigrant populations cut into vote totals for nationalist parties. Link.

– In Australia, ethnic diversity lowers social cohesion and increases “hunkering”, providing support for Putnam’s thesis finding the same results

After controlling for a self-selection bias, study finds that ethnic diversity in English schools reduces trust in same-age people and does not make White British students more inclusive in their attitudes towards immigrants. Link.

– In Germany, residential diversity reduces natives’ trust in neighbors, while it also reduces immigrants’ trust but through a different pathway. Link.

– Increasing social pluralism (diversity) is correlated with increased chance of collective violence. Link.

– “[E]thnic heterogeneity [diversity] explains 55% of the variation in the scale of ethnic conflicts, and the results of regression analysis disclose that the same relationship more or less applies to all 187 countries. … [E]thnic nepotism is the common cross-cultural background factor which supports the persistence of ethnic conflicts in the world as long as there are ethnically divided societies.” Link.

– Genetic Similarity Theory (GST) could help explain why diverse groups in close proximity increases ethnic conflict and ethnic nepotism. Link.

– Genetic diversity has contributed significantly to frequency of ethnic civil conflict, intensity of social unrest, growth of unshared policy preferences, and economic inequality over the last half-century. Link.

– Using social science data and computer modeling, researchers found that policies that attempt to create neighborhoods that are both integrated and socially cohesive are “a lost cause”. Link.

– The numbers and the genetic distance matter. Minority groups that get above a certain critical mass, and that are culturally distant from the majority culture, begin to self-segregate from the majority, moving society toward division and away from cooperation. Link.

Austrailian Study: “Our results provide at least partial support for Putnam's thesis.” https://www.tandfonline.com/doi/abs/10.1111/juaf.12015?journalCode=ujua20

“Diverse schools do not make White British students more inclusive in their attitudes on immigrants”…”Diverse schools reduce trust in people of one’s own age” https://www.sciencedirect.com/science/article/pii/S0049089X14001392

“trust is an integral part of a tight syndrome of social, political and economic conditions,”…“High trust countries are characterized by ethnic homogeneity, Protestant religious traditions, good government, wealth (gross domestic product per capita), and income equality,” https://www.deepdyve.com/lp/oxford-university-press/predicting-cross-national-levels-of-social-trust-global-pattern-or-bTNeBpb4Pa

“Increasing diversity undermines attitudes among stayers. Individuals who move from a diverse to a homogeneous community report improved attitudes. However, there is no effect among individuals who move from a homogeneous to a diverse community.” https://www.amren.com/news/2015/11/does-ethnic-diversity-have-a-negative-effect-on-attitudes-towards-the-community/