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Journal of Controversial Ideas

(ISSN: 2694-5991) Open Access Journal
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Controversial_Ideas , 5(3), 6; doi:10.63466/jci05030006

Article
Refugees’ IQs are Normatively Consequential
Tavren Oshal (pseudonym)
How to Cite: Oshal, T. Refugees’ IQs are Normatively Consequential. Controversial Ideas 2025, 5(3), 6; doi:10.63466/jci05030006.
Received: 18 December 2024 / Accepted: 23 September 2025 / Published: 11 November 2025

Abstract

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Responding to an article by Rindermann et al. (2024), which reports that refugees in Germany, on average, have significantly lower intelligence than the German host population, Bradley Hillier-Smith has argued that such cognitive disparities – if they exist – are irrelevant to states’ moral duties toward refugees. This article challenges his position. It further contends that even if we adopt a cosmopolitan perspective that denies states the right to prioritize the interests of their own populations, it is not clear that states in the Global North are morally required – or even permitted – to admit large numbers of relatively low-IQ refugees from the Global South. This, I show, is especially true given that assistance could instead take the form of supporting their relocation to a safe country within the region.
Keywords:
refugees; migration; intelligence; hereditarianism; innovation; Global South; nationalism; cosmopolitanism

1. Introduction

In a recent article in this journal, Heiner Rindermann et al. (2024) draw on three IQ-test studies to suggest that the cognitive ability of refugees in Germany tends to fall 12–15 IQ points below the national average. This is problematic, the authors argue, given that cognitive ability as measured by IQ-tests is “the best predictor and the most important causal factor in job performance, innovation, and breakthrough ideas” (Rindermann et al., 2024, p. 27), raising concerns that those refugees will impose net burdens on the German economy. To back up these worries, they reference projections indicating that Germany’s public liabilities could increase by around 9% due to the 2015–2016 immigration wave, while in the Netherlands, the average lifetime net cost per non-Western immigrant for society has been estimated at €275,000 (Rindermann et al., 2024, p. 7; Van De Beek et al., 2023).
In a detailed response, Bradley Hillier-Smith (2024b) seeks to show that even if Rindermann, Klauk, and Thompson are correct about refugees in Germany having, on average, considerably lower cognitive ability than the host population – which he, along with Turkheimer and Harden (2024) in another response article, spends some time questioning – and even if this prevents refugees from becoming net economic contributors, this is inconsequential for states’ moral duties towards refugees. Specifically, he believes that countries in the Global North would still be morally required to admit substantially greater numbers of refugees from the Global South than they do currently. In his words:
[E]ven if it could be established that certain refugees might have a lower IQ and thus would be less economically productive or would provide a less significant economic contribution as compared to the national average, the correct response from a moral and legal perspective is and must be “so what?” Those refugees are just as in need of, and entitled to, protection (Hillier-Smith, 2024b, p. 17).
One aim of the current article is to challenge this view. It argues that not only from a statist perspective, i.e., one requiring countries to show special concern to their own populations, but also from a cosmopolitan perspective that prohibits such favoritism (cf. Blake & Smith, 2022), for refugees to have IQs1 significantly below that of the host society’s average is normatively relevant. Additionally, it shows that much more research is needed to establish Hillier-Smith’s claim that it is morally required – or even permissible – for states in the Global North, broadly defined to include North America, Europe, Israel, Australia, New Zealand, Japan, South Korea, Taiwan, Singapore, and China, to admit substantially larger numbers of such refugees from the Global South, with “larger” understood relative to the size of a country’s current population. I will contend that this is particularly true when we recognize that refusing admission does not necessarily entail neglecting these refugees’ basic interests. Rather, it may involve supporting their resettlement in a safe third country in the Global South.
The remainder of this article is structured as follows. I begin by demonstrating that when refugees have a significantly lower IQ than the average of the would-be host society – I will henceforth refer to such individuals as “relatively low-IQ refugees” – the case for admitting them is significantly weakened from a statist or nationalist perspective (Section 2). Next, I argue that even when we adopt a cosmopolitan perspective, it remains unclear whether countries in the Global North are morally required, or even permitted, to take in large numbers of relatively low-IQ refugees from the Global South (Section 3). I conclude with some clarificatory comments on these findings (Section 4).

2. The Statist/Nationalist Case against Large-Scale Admission

As mentioned, Hillier-Smith believes that even when a relatively low IQ prevents refugees from making a net contribution to the economy of their potential host society, this fact is normatively irrelevant. On page 15, he motivates this view, writing that:
the avoidance of economic costs arguably lacks the moral significance to justify excluding immigrants in the first instance, and a fortiori lacks the moral significance to justify excluding refugees seeking safety (let alone justify harming them through practices to prevent their accessing protection). Indeed, to suppose that the avoidance of economic costs alone has the requisite moral significance to justify refusing protection to refugees would violate the plausible limits of agent-relative permissions. Even if a state has an agent-relative permission to give priority to its own citizens’ interests over those of outsiders, this priority cannot plausibly be absolute. To hold that avoiding economic costs could justify the exclusion of refugees would entail holding that the economic interests of citizens are sufficiently more morally important than, and are thus able to override, the urgent interest of refugees to avoid the harms of abuse, violence, torture, rape and sexual violence, a lack of security and subsistence, and, in some cases, death. Such a priority weighting of citizens’ interests would discount refugees’ most fundamental interests and human rights to an implausible extreme, as if they counted for almost nothing (Hillier-Smith, 2024b, p. 15).
Although what is meant by “economic costs alone” is not specified, the most plausible interpretation, it seems to me, is that admitting relatively low-IQ refugees would make people in the Global North worse off but still allow them to enjoy a fairly good quality of life. This is supported by Hillier-Smith’s remark earlier in the paper that “states in the Global North have the capacity and resources to provide … protection and assistance [to refugees] at relatively little cost to themselves” (Hillier-Smith, 2024b, p. 12). So, rather than owning two cars (one can imagine), residents of these countries might become able to afford just one, or perhaps be required to sign up to a car-sharing scheme; rather than being able to go on holiday to an exotic destination each year, they might need to spend their holiday closer at home; rather than buying their clothes new, they might need to buy them at a second-hand store; and so on. Insofar as these kinds of sacrifices are the only ones people in the Global North must bear by admitting refugees likely to impose net fiscal burdens, then at least as long as there are no other refugees who can be expected to have neutral or positive economic impacts, I agree that justifying their exclusion becomes difficult. To deny refugees admission based on such anticipated lifestyle changes would, as Hillier-Smith writes, discount their interests implausibly strongly even if we accept, as defenders of statist or nationalist conceptions of justice maintain (e.g., Miller, 1995), that we have an agent-centered prerogative to show a certain degree of partiality towards our fellow citizens and residents.
The problem with this view is that if the per capita net lifetime costs of admitting refugees with significantly below-average IQs amount to hundreds – or even merely tens-of-thousands of euros, it is unlikely that the impact on the host population will be confined to such minor consequences. Thus, if Van De Beek et al.’s (2023) calculation that the average net lifetime cost per non-Western immigrant in the Netherlands equals €275,000 is only broadly correct, then notwithstanding the fact that the Netherlands boasts one of the highest GDPs per capita (Our World in Data, 2023), this is almost certain to impose a morally significant toll on some of its residents. To appreciate this, note that even the wealthiest countries have significant portions of their populations living below the poverty line, and the Netherlands is no exception. According to current estimates, approximately 540,000 Dutch people out of a population of circa 17 million fall into this category (CBS, 2024). Additionally, those who qualify for social housing usually face long wait times – more than half have already been waiting over three years, and it is not uncommon for people to wait as long as ten years (Klapwijk, 2023) – while refugees are frequently given priority (NOS, 2025). Since additional housing cannot be built overnight and tends to be challenging to construct due to opposition from local residents (Esaiasson, 2014) and strict (EU-imposed) environmental regulations – particularly those related to nitrogen levels, as the Netherlands has repeatedly exceeded EU thresholds for nitrogen emissions, leading courts to block or delay many housing projects that would contribute to further nitrogen deposition (Consortium PBL-RIVM-WUR, 2024) – this scarcity is unlikely to be resolved anytime soon.
But it is not only the domestic poor who may be affected. Even those who do not belong to the lowest socioeconomic classes can find themselves struggling to afford expensive, life-saving medications or treatments. Insofar as the economic costs of admitting large numbers of relatively low-IQ refugees reduce their overall spending power, this could have life-threatening consequences for such individuals. Additionally, one would expect the admission of this group to lead to at least somewhat higher crime rates and a decline in public safety, as numerous studies have established a positive correlation between lower IQ and an increased likelihood of criminal behavior, including violent offenses (Frisell et al., 2012; Jacob et al., 2019; Ttofi et al., 2016). For example, analyzing data from the 2007 Adult Psychiatric Morbidity Survey conducted in England, Jacob et al. (2019) found that violent behavior decreased linearly as IQ levels increased, with individuals scoring 70–79 having 2.25 times greater odds of committing violent acts than those with scores of 120–129, even after adjusting for multiple factors.
A critic might acknowledge these risks but contend that governments can prevent some of them by providing vulnerable members of society with stronger protections. They might do so, for instance, by increasing socioeconomic redistribution; implementing (or raising) minimum wages to reduce the number of individuals relying on welfare benefits; and expanding public investments in social housing, aged care, and life-saving medicines and medical treatments.
My rejoinder is that even if such protective policies are ideally pursued – which those who regard a more laissez-faire or capitalist economic approach as the best way to improve everyone’s living standards will deny (e.g., Brennan, 2014) – the likelihood that governments will be both willing and able to go so far as to prevent the high costs of mass low-IQ migration from significantly worsening conditions for some residents in precarious situations appears bleak, as such migration would severely strain public resources needed to support them. To see this, notice that even rich countries with some of the most generous welfare systems, such as those in Scandinavia, are already struggling to eliminate poverty (Save the Children, 2023) and guarantee access to aged care and essential health services for all (Hunter, 2024). For example, in Sweden, nearly 6% of households in the lowest income quintile have faced “catastrophic health expenditures,” defined as out-of-pocket healthcare costs exceeding 40% of their capacity to pay (Häger Glenngård & Borg, 2019). Furthermore, in a country like the Netherlands, which is one of the most densely populated and, as previously mentioned, is experiencing serious environmental challenges, housing large numbers of new refugees can easily lower quality of life by increasing the already substantial congestion and further straining the natural environment.
The upshot is that while it may not be strictly inevitable that admitting large numbers of relatively low-IQ refugees will threaten the ability of some residents in the Global North to maintain a safe, crime-free standard of living – and, in some cases, even to survive – this is a foreseeable outcome which, from the non-ideal theory perspective adopted in this article (cf. Simmons, 2010; Thompson, 2020), must be factored in and assigned considerable weight if we endorse a statist or nationalist conception of justice.

3. The Cosmopolitan Case against Large-Scale Admission

In response, our critic might concede all this but argue that if we accept a cosmopolitan framework, i.e., one that bars states from prioritizing the interests of their own populations, it remains morally incumbent on Global North countries to accept vastly more refugees from the Global South than they currently do irrespective of their intelligence levels. On this view, if Hillier-Smith is right that “refugees' rights against sexual violence, torture, and other extreme harms are persistently violated without protection or recourse” (Hillier-Smith, 2024b, p. 12), which appears true in various parts of the world (e.g., IOM et al., 2020; Ragozzino & Pappier, 2023), then a great many – potentially tens of millions if not more – relatively low-IQ refugees could be admitted before the circumstances of the domestic poor and other vulnerable groups in the Global North become as dire as theirs. In support of this claim, our critic might note that while many people in the Global North face tough conditions, their situations remain generally much better than those experienced by refugees. Consider the previously mentioned poverty rates in the Nordic countries; although harmful, the percentage of people in these countries estimated to live in absolute poverty, as opposed to relative poverty, is less than 1%, compared to 40–80% in large parts of sub-Saharan Africa (Our World in Data, 2024). Likewise, while the situation for many older adults in the Global North may be difficult due to caregiver shortages (AARP & National Alliance for Caregiving, 2025; OECD/European Commission, 2024), the predicament of those fleeing war, civil unrest, or political persecution is often significantly worse still.
What to make of this reply? While these average welfare disparities are difficult to dispute, we should be careful not to overstate the number of relatively low-IQ refugees from the Global South who can be admitted before – even from a cosmopolitan perspective, where everyone’s wellbeing is weighted equally – the benefits of further admissions are outweighed by the combined costs to (i) the refugees themselves, (ii) the existing inhabitants of countries in the Global North, and (iii) those who remain in the Global South. (Notice that I restrict my focus here to personal or individual costs to avoid relying on controversial utilitarian principles of aggregation on which small personal benefits for a sufficiently large number of individuals can justify the imposition of substantial personal costs on a smaller group; cf. Scanlon, 2000).
To demonstrate that the cosmopolitan threshold beyond which states in the Global North are no longer morally obliged to admit relatively low-IQ refugees from the Global South – at least not on the basis of beneficence, which is the focus of this article – 2 is reached sooner than advocates of large-scale refugee acceptance typically acknowledge, several observations are in order.

3.1. IQ-Related Obstacles to Thriving in the Host Society

The first is that for refugees to possess a substantially lower IQ than the average member of the host society – and Rindermann et al.’s estimated 12–15 point deficit for refugees who arrived in Germany during the 2015 migrant crisis certainly qualifies as such – renders it much harder for them to particulate on full and equal terms in society than if their IQ were comparable to, or higher than, the national average. Christopher Heath Wellman highlights one reason for this in his response to Rindermann et al.’s article, noting that individuals with below-average cognitive abilities are less likely to benefit from opportunities for advancement in society compared to those with average or above-average cognitive abilities (Wellman, 2024, p. 2). To appreciate this, it should be mentioned that across different ethnic and racial groups (Hunt, 2010; Murray, 2021; Weiss & Prifitera, 1995), IQ is the most important predictor of and contributor to people’s life outcomes, including their educational outcomes, socioeconomic success, and occupational status (Belsky et al., 2018; Plomin & von Stumm, 2018; Warne, 2021, p. 480). What is more, a difference of 12–15 IQ points is far from trivial. To put it into perspective, Wolfram (2023) finds that in the UK, a difference of 12 IQ points roughly corresponds to the gap in intelligence between a medical practitioner (IQ ≈ 112) and a nurse (IQ ≈ 100) or that between a hotel and accommodation manager (IQ ≈ 102) and a domestic cleaner (IQ ≈ 90). Consistent with such disparities, Rindermann et al. (2024) present different sources of evidence indicating that large portions of refugees and migrants in Germany are struggling educationally and professionally.
A further difficulty here is that cognitive disadvantages relative to host populations, along with the related economic disadvantages, frequently persist across generations (Jones, 2022; Rindermann & Thompson, 2016; Zhou & Gonzales, 2019). For example, Rindermann and Thompson (2016) report only a 1.84 IQ point increase from the first to the second generation of immigrants. As a result, such disparities often take at least three or four generations to close, if they close at all – which not all studies find they do; in fact, Figlio and Özek (2020) report a successive reduction in achievement across immigrant generations.
One reason this intergenerational persistence is relevant – others will be discussed later – is that it suggests not only the relatively low-IQ refugees themselves are likely to struggle to participate fully and equally in society. The same will apply in many cases to their children, grandchildren, and even great-grandchildren, who are also likely to have below-average IQs. Since people’s welfare tends to be significantly influenced by how their posterity fares – most of us deeply care about the wellbeing and success of our children, grandchildren, and great-grandchildren) – this can be expected to further reduce the benefits of admission compared to a counterfactual scenario where the refugees’ IQs are broadly similar to, or higher than, the host population’s average. (To avoid confusion, this does not mean that any integrative challenges faced by refugees’ descendants matter solely because of the indirect impact on their parents’, grandparents’, or great-grandparents’ wellbeing; they also matter because these descendants are distinct individuals with moral significance.)
Some might argue that persistent interethnic and interracial gaps in cognitive performance and, downstream from this, economic disparities, stem (mostly) from discrimination against refugees and immigrants and conclude that the appropriate response is to intensify efforts to combat such discrimination rather than to restrict immigration. Ways of achieving this could include, among others, increased diversity, equity, and inclusion (DEI) training, expanded initiatives to decolonize educational curricula, and stricter penalties for those who commit microaggressions.
Alternatively, the disparities in question might be largely, if not entirely, attributed to cultural differences between ethnic and racial groups (Sowell, 2013). From this perspective, governments may need to focus instead on encouraging groups with weaker cognitive and economic outcomes to adopt cultural traits linked with stronger outcomes, such as an emphasis on academic achievement. Potential measures could include promoting these desirable traits through public media campaigns and the school system; dispersing refugees across the country to help prevent the formation of ethnic enclaves; scaling back cultural accommodations and subsidies in order to incentivize integration into cognitively and economically better-performing domestic cultures; and encouraging members of high-performing groups to assume roles where they can transmit aspects of their culture to others – for example, Ashkenazi Jews, who have the highest average IQ globally (Winegard et al., 2020, p. 6), might be given special subsidies to work as nannies or educators for families from other backgrounds.3
My rejoinder is that even if discrimination and cultural differences are relevant, it is far from clear whether they are the only causes of the observed disparities or even the most important ones. Despite far-reaching attempts to suppress research into group-level intelligence differences (e.g., Carl & Woodley of Menie, 2019; Cofnas, 2020; Lee, 2022), many studies have emerged supporting the so-called “hereditarian thesis.” According to this thesis, just as genetic factors contribute significantly to individual differences in intelligence (Haier, 2017; Pesta et al., 2020; Plomin & Deary, 2015) – with heritability estimates in high-income countries often reported in the range of 0.6–0.8 in adulthood (Plomin & Deary, 2015), so they do so for observed intelligence differences between racial or ancestral groups. Specifically, across the world, individuals with predominantly Ashkenazi Jewish and East Asian ancestry exhibit higher average IQs than those with predominantly non-Jewish European ancestry, who in turn have higher average IQs than those with predominantly African ancestry. While the distributions of all these groups overlap, the average differences between the highest- and lowest-performing groups are considerable, generally estimated at two to three standard deviations (Hunt, 2010; Murray, 2021; Warne, 2021), and consistent with findings from student assessment studies such as Programme for International Student Assessment (PISA) and Trends in International Maths and Science Study (TIMSS) (Gust et al., 2022; Rindermann, 2018).
Several lines of evidence for genetically influenced racial differences in intelligence, which in one anonymous survey are accepted by 90% of intelligence scholars (N = 71),4 are discussed in three recent literature reviews, all of which conclude in favor of a partial yet meaningful genetic explanation (Connor, 2023; Warne, 2021; Winegard et al., 2020). Although examining all the evidence for hereditarianism presented in these and other studies lies beyond this article’s scope, it is important to consider some of the main supporting findings. The reason is that if hereditarianism is false, it might well be preferable for states in the Global North to admit many more refugees from the Global South than they currently do while intensifying efforts to eliminate the environmental factors wholly responsible for interracial gaps in cognitive performance.
Without aiming for an exhaustive list, then, findings that support the existence of genetically influenced racial differences in intelligence include:
  • The recalcitrance of the Black–White IQ gap in the US, which has persisted at about one standard deviation since the 1990s, despite major social and educational advances for African Americans and decades of affirmative action. A recent literature review (Jay, 2022) reports that this gap emerges before preschool age and remains even after controlling for factors such as school quality and parental socioeconomic status. (Furthermore, because socioeconomic status itself shows substantial genetic influence (Plomin, 2018; Trzaskowski et al., 2014), even its contribution to the IQ gap cannot be regarded as entirely environmental.)
  • The ubiquity of racial differences in intelligence across the world. As noted, these differences do not only include the Black–White gap, but also gaps favoring East Asians and Ashkenazi Jews over Gentile Whites.
  • The fact that racial differences are most pronounced in the parts of IQ tests with a higher g-factor loading, i.e., those with the higher heritability, rather than those assessing more culturally influenced forms of intelligence.
  • Studies showing that modern day intelligence tests have measurement invariance across racial groups, meaning that divergent outcomes are not attributable to test bias (e.g., cultural or linguistic).
  • The persistence of substantial racial differences even in affluent societies where the influence of shared environments compared to genes and non-shared environments is found to be small.
  • Admixture studies demonstrating that genetic ancestry is a stronger predictor of cognitive differences than self-identified race, and that these effects cannot be explained by skin color discrimination.
  • Genomic research showing a significant rise in intelligence-related polygenic risk scores in the European population over the past 10,000 years, likely driven by urbanization and occupational specialization (Kuijpers et al., 2022),5 which is unlikely to have occurred universally or simply not to the same extent everywhere due to large differences in natural and cultural environments during this period.
  • The fact that there are strong and widely recognized genetic influences on numerous other, not politically controversial, phenotypic racial differences (e.g., Fan et al., 2016; Reich, 2018; Stæger et al., 2025), including on ones that like intelligence are polygenic, such as height, bone density, musculature and fat distribution, facial structure, skin pigmentation, hair thickness and structure, immune system response, drug metabolism, cold and heat tolerance, altitude adaption, and circadian rhythm and sleep patterns.
At the same time, while hereditarianism has been criticized (e.g., Bird, 2021; Flynn, 2016; Nisbett et al., 2012), a serious environment-only competitor has failed to emerge. Specifically, environmental explanations for interracial differences in cognitive performance have generally been shown to have weak effects at best, such as the influence of stereotype threat (Shewach et al., 2019) and differences in lead exposure (Jenson et al., 2025). Hillier-Smith’s (2024b, p. 4) own suggestion is that trauma may be the primary factor behind the below-average IQs of recent refugees in Germany. However, this explanation raises the question of why Ashkenazi Jews in Western countries and Chinese diasporas in Southeast Asia have historically outperformed native populations educationally and economically even during or after periods of severe discrimination and repression (Chin, 2022; Jones, 2022; Winegard et al., 2020).6 Additionally, it is inconsistent with research by Barel et al. (2010) showing that, despite reporting “substantially more posttraumatic stress symptoms,” Holocaust survivors did not exhibit reduced cognitive functioning compared to those without a Holocaust background. Finally, it fails to account for evidence suggesting that North Koreans are significantly more cognitively gifted on average than most sub-Saharan African populations despite experiencing similar levels of poverty and enduring what is perhaps the world’s most brutal dictatorship – conditions one might assume to be highly traumatizing for many residents. Among this evidence is the country’s advanced weapons manufacturing industry, which has successfully developed nuclear weapons and produces ballistic missile technology for other countries, and its strong performance in the International Mathematical Olympiad (as of February 2025, it has won eight gold medals in the last ten editions – eight times more than all of Africa combined and surpassing wealthier, more populous nations like France and Germany), which is closely linked to national IQ (Rindermann, 2011).
In short, even if the debate between hereditarianism and environment only-theories remains to be decided, there are compelling reasons to worry that the relatively low intelligence of many refugees from the Global South is significantly influenced by genetic factors. As noted, this is relevant because it suggests that the intergenerational persistence of disadvantage among various immigrant communities from the Global South may be difficult, and perhaps impossible, to overcome through environmental interventions, such as increased investment in anti-discrimination measures and efforts to alter the people’s cultures, which also risk infringing on fundamental liberties. To be clear, it does not necessarily follow from this that such interventions should be avoided altogether, as they might still have some effect. However, it does suggest that regardless of how supportive Global North countries are toward relatively low-IQ refugees from the Global South, many of these individuals – and their descendants – are likely to face cognitive limitations in their ability to thrive within these societies. (An illustrative example may be provided by migrants from Somalia, a country with one of the lowest recorded intelligence levels globally: in 2018, nearly 50% of Somalis living in Denmark were in long-term unemployment (Regeringen, 2018), while in the US, they have the lowest level of educational attainment among all sub-Saharan African groups, with only 14% holding a bachelor's degree or higher, and the highest poverty rate at 37% (Batalova & Lorenzi, 2022).)7

3.2. Reductions in the Host Society’s Living Standards

Thus far, this section has examined how having significantly below average intelligence makes it challenging for individuals to fully and equally engage in society, thereby limiting the ability of refugees with IQs well below the host society’s average to flourish. What I want to suggest now is that when relatively low-IQ refugees from the Global South settle in large numbers in the Global North, this is likely to have negative social effects that further reduce their expected quality of life, while also negatively affecting the quality of life of existing members of society.
To be sure, some of these effects could be more closely tied to such refugees being generally of a different ethnicity than to their possession of relatively low IQs. For instance, a recent meta-analysis covering 87 studies from various countries found “a statistically significant negative relationship between ethnic diversity and social trust across all studies” (Dinesen et al., 2020). Although more research is needed to assess whether ethnic diversity among high-IQ groups also diminishes trust, it is possible that such effects stem mostly from ethnic diversity itself rather than from its interaction with cognitive disparities – one piece of evidence for this is that possessing higher intelligence levels than the native populations has not prevented the Chinese in Southeast Asia or Ashkenazi Jews in Europe from experiencing pogroms and other forms of hostility (Chin, 2022; Jones, 2022). At the same time, people in countries like the UK hold significantly more positive attitudes toward high-skilled migrants than low-skilled ones (Richards et al., 2023), suggesting intelligence levels could play an important role. What is relevant for us is that, regardless of the exact causes, declining social trust is likely to reduce quality of life for immigrants and native populations alike. Similarly, when mass immigration from the Global South contributes to interethnic tensions and hostility – including nativist backlashes, as recently witnessed in the anti-immigrant riots in the UK and Ireland (BBC, 2024; Bloomberg, 2024) – this may negatively affect everyone in society. As Eric Kaufmann's work demonstrates, such conflicts are difficult to prevent once immigration from culturally and ethnically distinct regions starts to reach high levels and bring about rapid demographic change, even if governments have a certain degree of control over their intensity (Kaufmann, 2018).
In contrast, other negative social effects of mass migration from the Global South are unambiguously linked to people’s intelligence levels. If, as studies such as those by Van De Beek et al. (2023) and Rindermann et al. (2024) indicate, relatively low-IQ refugees impose substantial net fiscal burdens on their host societies due to cognitive barriers to economic participation, this will reduce overall wealth in those societies, making them less attractive places to live for all. This is especially true given the discussed tendency of such IQ disadvantages to be intergenerationally transmitted, which I argued in the previous subsection may only be partially remediable through environmental interventions if hereditarianism is correct. Additionally, we saw in Section 2 that lowering a society’s intelligence levels can be expected to lead to an increase in crime, including violent offenses, which is also likely to harm members of both native and immigrant populations.
A last significant way in which the admission of large numbers of refugees from the Global South can be anticipated to undermine living conditions in the Global North is based on Garett Jones’s (2022) finding that immigrants and their descendants have a proclivity to make their destination countries a lot more like their countries of origin. Drawing on longitudinal, historical, and cross-country studies (e.g., Algan & Cahuc, 2010; Costa-Font et al., 2018; Fuchs-Schündeln et al., 2020; Giavazzi et al., 2019; Ljunge, 2014; Moschion & Tabasso, 2014), Jones demonstrates that even after four generations, descendants of immigrants largely maintain cultural attitudes and preferences regarding trust, saving, and the role of government resembling those of people in their ancestral homelands, as measured by large-scale surveys such as the World Values Survey. This, he goes on to show, transforms their host societies’ political and economic institutions for good or for bad. Whereas immigrants coming from countries marked by high levels of trust and saving and low levels of corruption, such as Northern Europe and East Asia, tend to raise institutional quality as exemplified by e.g., the economic influence of Chinese immigrants in South-East Asia, those coming from countries with low levels of trust and saving and high levels of corruption tend to reduce it. Since most refugees from the Global South hail from countries in the latter category, this research suggests that their large-scale admission is likely to have a negative impact on institutional quality in the Global North.8
A critic may respond that this problem could be addressed by enforcing strict integration or assimilation requirements. However, aside from raising concerns about violations of fundamental liberties, the effectiveness of such requirements remains doubtful. Not only do many people feel a strong connection to their cultures and desire to pass them on to their children (Kymlicka, 1995), cultural attitudes and preferences are often influenced genetically through processes of gene–culture co-evolution (Boyd & Richerson, 2008),9 and they can also be shaped biologically through the effects of early cultural exposure and social learning on brain structure and function (Henrich, 2020).
Alternatively, it might be argued that the negative effects on institutional quality could be avoided by keeping immigrants and their offspring permanently disenfranchised through denial of a path to citizenship. This has long been the approach of the Arab Gulf Monarchies (Ali & Cochrane, 2024). Yet, apart from raising serious moral objections as well, at least in liberal democracies – which constitute the majority of states in the Global North – this is exceedingly unlikely to happen due to their commitment to political equality.

3.3. Costs to People in Other Societies

What I want to propose next is that if, as is necessary from a cosmopolitan perspective, we also consider the interests of people in societies beyond the host country and give equal weight to everyone’s interests, it becomes even less clear that states in the Global North are morally obliged to admit large numbers of refugees from the Global South. Wellman (2024) discusses one possible reason for this. Citing Rindermann et al.’s finding that refugees in Germany – while significantly less intelligent on average than the native population – still score 5–10 IQ points higher than those who remain in their countries of origin, he argues that because individuals with greater cognitive ability are more likely to create effective economic and political institutions, such brain drains may “impede the construction of the desirable institutions needed for more opportunities where they are already in desperately short supply” (Wellman, 2024, pp. 2–3). From this, he goes on to conclude that instead of permitting large-scale migration from the Global South to the Global North, a preferable alternative – most famously defended by David Miller (2016) – might be for states in the Global North to focus more of their efforts on improving living conditions and economic opportunities within the Global South.
Due to the scope and space constraints of this article, I cannot provide an assessment of this argument here. Instead, I will use this opportunity to present another argument against admitting large numbers of refugees from the Global South that, like Wellman’s, takes into account the interests of people outside the host country. Central to this argument is an already discussed finding by Jones (2022), namely that immigrants and their descendants shape their destination countries economically and politically to resemble more closely their countries of origin. Since nations in the Global South are characterized by poor economic and political performance, this research suggests that for people in these countries to move in large numbers to countries in the Global North can be expected to weaken the quality of local institutions. Earlier, we looked at one noteworthy implication of this: the more refugees from the Global South are admitted by states in the Global North, the harder it is likely to become to sustain a society where both they and other residents can enjoy a good, or even just decent, quality of life. What is pertinent for current purposes is that there are also significant consequences for those who remain in the Global South.
To appreciate this, it should be observed that the global innovation landscape is heavily dominated by countries in the Global North. Data from the UNESCO Institute of Statistics reveals that in 2019, sub-Saharan Africa and Central Asia accounted for the smallest shares of research and development (R&D) investments, contributing just 0.8% and 0.1% of global R&D funding, respectively, while around 80% of global R&D spending was concentrated in approximately 10 countries, with North America and Western Europe making up 46.1% and East Asia and the Pacific contributing 40.6% (Acharya & Pathak, 2019). What this means is that the Global South is scientifically and technologically strongly dependent on the Global North, whose innovations have been shown to eventually spread worldwide albeit with some delay (Boutellier & Heinzen, 2014; Hall et al., 2010; Skare & Soriano, 2021), including within sectors crucial to the wellbeing of those living in the Global South such as green innovation, disease protection, and food production (Witajewski-Baltvilks & Fischer, 2023). Because of this dependency, it is not just vital for residents of the Global North but for people everywhere that nations in the Global North, especially the United States, China, France, Germany, Japan, South Korea, and the United Kingdom, sustain their current levels of innovation.
However, if admitting large numbers of refugees from the Global South weakens the political and economic institutions of those countries, then, as Jones (2022, ch. 6) observes, this is likely to diminish their innovative output, an effect that could be further compounded by a reduction in national resources for research and development if estimates such as Van De Beek’s regarding the net economic impact of these refugees are broadly accurate (see Section 1). This is because, as studies such as those of Tebaldi and Elmslie (2013) and Cong Wang (2013) indicate, institutional quality plays a major role in fostering innovation. Tebaldi and Elmslie tested whether good institutions – as measured by factors such as the protection of property rights, the promotion of market-friendly policies, the control of corruption, and the effectiveness of the judiciary system collectively drive an economy's rate of innovation – merely correlate with innovation or actively drive it. Their findings reveal that institutional quality remains a significant predictor of patents even when accounting for geographic variables (Tebaldi & Elmslie, 2013). Wang extended this analysis using fixed-effect panel regressions, which compare countries to themselves over time, and found further evidence for a “significant direct effect of institutions on R&D intensity” (Wang, 2013, p. 128). His study shows that improvements in governance, as measured by indices like the World Bank’s governance indicators, the International Country Risk Guide (ICRG), and the Polity index, consistently predict increases in R&D spending and patenting even when controlling for religion, legal origin, geography, human capital, and openness to trade and financial development.
What is important for us is that, if these studies are correct, for Global North states to admit, or continue admitting, large numbers of refugees from the Global South – as e.g., Sweden has done over the past two decades, which has raised the non-Western population from 2% to 15% (Economics Observatory, 2023; Sanandaji, 2018) – this could eventually harm people worldwide, including those in the Global South, by slowing innovation through the anticipated negative effects on economic and political institutions in the Global North (Jones, 2022). When we further consider that:
1
even if countries in the Global North were to admit all refugees from the Global South – who account for the great majority of the 43 million refugees worldwide (UNHCR, 2025) – the remaining population of the Global South, roughly 5.7 billion excluding China and about 7.1 billion including it as of early 2025, would still be vastly larger and expected to become larger still because of the Global South’s higher fertility (Roser, 2024),
And that
2
many of these stay-behind individuals will be among the globally worst off,
it becomes questionable even from a cosmopolitan perspective whether Global North countries are morally required, or even permitted, to take in large numbers of refugees from the Global South. This, it is worth emphasizing, is not changed by the potential benefits for the countries of origin, such as remittances, diaspora networks, and skills transfers (if refugees eventually return) (Docquier & Rapoport, 2012). Not only are there cross-national studies showing that, even after accounting for potential reverse causality, a higher remittance-to-GDP ratio is associated with lower levels of control of corruption, government effectiveness, and rule of law (Abdih et al., 2012). The aforementioned fact that the entire Global South, along with the rest of the world, ultimately benefits from and relies on innovations originating in the Global North – which have already raised global living standards dramatically over the past two centuries (Pinker, 2018) – suggests that protecting innovation in this region, including advances to combat climate change, strengthen disease prevention, and secure adequate food production for global needs, constitutes a global priority.
Some might accept this but argue that, provided refugees from the Global South are distributed widely enough across countries in the Global North, none of these societies would have to admit numbers large enough to significantly impair global progress in research and development.10 Alternatively, such harm may be avoided by concentrating refugees from the Global South in those Global North countries that make relatively low contributions to global innovation.11
One rejoinder is that, even if these claims are true, the high stakes for humanity as a whole make it imperative to have evidence for them – evidence that, to the best of my knowledge, has not yet been provided. To illustrate this, consider that an estimated 9 million people die each year of hunger (WFP, 2021), between 5.7 and 8.4 million deaths occur annually in low- and middle-income countries due to poor-quality health care (WHO, 2025), and an additional 250,000 deaths per year are projected between 2030 and 2050 as a result of climate change (WHO, 2023). Against this background, even modest delays in global innovation in areas such as food production, health care, and climate change mitigation – whether by a year or even just a month – can exact a tremendous human toll, one that is only likely to grow given that more than half of the world’s refugees originate from two regions, Africa and the Middle East, where – unlike in the Global North – fertility rates remain above replacement levels (Roser, 2024). What this suggests is that, rather than assuming that admitting refugees from the Global South will safeguard the basic interests of more people, we need credible projections supporting this assertion. Such projections should assess how admitting different numbers of refugees from various parts of the Global South would affect the scientific and engineering accomplishments of specific host countries in both the short and long term, taking into account factors such as:
  • The extent to which hosting the refugees is likely to reduce the financial resources available for research and development.
  • The degree to which the refugees exhibit traits that could undermine the host country’s institutional quality and, ultimately, its innovative capacity.
  • The extent to which the refugees possess other, beneficial traits that might at least partially offset potential negative effects on institutional quality.
  • The anticipated scale of family reunification and marriage migration.
  • Potential differences in fertility rates between the refugees and the native population.
  • The expected levels of emigration/remigration within both groups.
Another rejoinder is that even if admitting refugees from the Global South could reasonably be expected to yield better outcomes than inaction, it must still be demonstrated that this course of action is preferable to an alternative means of assisting this group. This is to help such individuals relocate to a safe third country in the Global South – ideally one with linguistic, cultural, and religious similarities, as well as comparable intelligence levels, to support their and their descendants’ participation in the local economy and overall integration (see Section 3.1). While more research on this topic is needed, there are several reasons for thinking this approach may be preferable. First, resettling refugees in the Global South seems to better protect the institutional quality and innovative output of states in the Global North. Second, it allows these states to assist substantially more refugees with the same resources, given the much lower cost of living in the Global South (Betts & Collier, 2018). Third, it may discourage many individuals from undertaking dangerous journeys to the Global North, such as treacherous Mediterranean crossings where thousands die each year attempting to reach countries like Spain, Italy, and Greece (Koopmans, 2023).
There is no guarantee, of course, that countries in the Global South will be willing to admit (enough) refugees. That said, the substantial financial incentives that Global North states can offer, along with the political and economic influence they can exert, provide grounds for optimism that – if serious efforts are made – appropriate safe havens may often be secured. Moreover, there are various recent cases in which Global South states have agreed to such arrangements in exchange for financial support – including the EU–Turkey deal, the EU–Jordan and EU–Lebanon compacts, and the UK–Rwanda arrangement – though some have questioned whether these destination countries are sufficiently safe. Finally, even if securing willing hosts in the Global South proves difficult, or if the countries that do consent to host are simply not as safe as those in the Global North, this need not count decisively against the current option. Given that most, if not all, contemporary states in the Global North appear highly reluctant to accept (significantly) more refugees from Global South (Varma & Roehse, 2024) – including Germany and Sweden, which have previously admitted large numbers – pursuing this strategy may still represent the most realistic way of improving these individuals’ lives.

4. Final Remarks

This article has defended two claims: (i) that refugees’ IQs are normatively relevant when deciding about their admission, and (ii) that it is not clear whether states of the Global North are morally required, or even permitted, to admit large numbers of relatively low-IQ refugees from the Global South. I began by showing that if, as recent research by Jan Van De Beek indicates, such refugees are likely to impose fiscal burdens on their host society amounting to tens- if not hundreds-of-thousands of euros over the course of their lives, this will not merely condemn its existing members to a life of somewhat lower luxury. For some of these individuals, their admission can be expected to exact a high personal toll, such as those living below or near the poverty line; those in need of social housing but unable to access it due to long waiting lists; those struggling to afford expensive life-saving medicines or medical treatments; and those falling victim to the anticipated rise in crime, given the negative correlation between intelligence and criminality. Depending on how much special concern, if any, one thinks states may or should show to their existing populations, these consequences can substantially limit the number of refugees whom they are morally required or even permitted to admit.
But that is not all. I went on to demonstrate that even from a cosmopolitan perspective, countries in the Global North might not be morally obliged, or even allowed, to admit large numbers of relatively low-IQ refugees from the Global South. Apart from the fact that having below-average intelligence makes it more difficult for such refugees – and also their descendants – to participate as full and equal members in the host society, hosting substantial numbers of them risks lowering everyone’s quality of life in society. This was found to be due to a higher likelihood of various negative downstream effects, including an erosion in social trust; an increase in nativist anti-immigrant hostility; a rise in crime; and a reduction in national prosperity. Additionally, we saw that through the cultural transplant mechanism described by Garett Jones and other scholars, accommodating large numbers of refugees from the Global South risks weakening the political and economic institutions of the Global North. This was shown to be problematic not only because of the direct impact on those living under them, but also because these institutions are indispensable for sustaining the innovation required to address critical global challenges – such as climate change, disease prevention, and food security – which might be undermined further by the anticipated decreases in national prosperity.
I want to end with some clarificatory comments on these findings. The first is that my defence of the normative significance of refugees’ IQs has not relied upon the fact that admitting those with comparatively low intelligence may increase levels of social inequality (Wellman, 2024). While I am personally less moved by egalitarian concerns than most contemporary moral or political philosophers, insofar as one thinks that such inequality is highly troublesome (e.g., Anderson, 1999; Scanlon, 2017; Temkin, 2003), this will give one further reason to accept my conclusions.
Secondly, I have not presupposed either that, all else being equal, individuals with lower intelligence should receive less moral consideration than those with higher intelligence. While I found that differences in intelligence levels are relevant when deciding how many refugees from the Global South to admit, this was not because I assumed more intelligent individuals to be morally superior.
Thirdly, this article has not engaged with Hillier-Smith’s argument that states in the Global North may be morally required to admit large numbers of refugees from the Global South – regardless of their intelligence levels – on the ground that their efforts to keep them out are harming these individuals (Hillier-Smith, 2024b; see also Hillier-Smith, 2024a). Although an in-depth discussion of this issue is beyond this article’s scope, one thing to say is that if the border policies of states in the Global North are indeed causing harm as opposed to merely allowing harm to occur (cf. Woollard & Howard-Snyder, 2021), my findings suggest that the proper response may be for them to adopt more humane exclusionary measures as opposed to opening their borders. Another thing to say is that insofar as such policy changes are unlikely to materialize, maintaining current exclusionary practices could still be the lesser evil, given the serious danger that large influxes of relatively low-IQ refugees from the Global South will weaken local political and economic institutions and ultimately hinder innovation in the Global North on which the whole of humanity depends for its future welfare. (Whereas hard-nosed deontologists will be unmoved by such considerations – in their view, one may never (wrongfully) cause harm even if the heavens were to fall – other deontologists might accept this conclusion based on their endorsement of threshold deontology, which holds that rights violations become permissible when necessary to produce sufficiently large benefits; cf. Alexander, 2000; Zamir & Medina, 2010).
The fourth and final comment has already been made but is worth reiterating given its importance. This is that nothing I have said precludes that states in the Global North should take action to improve the lot of refugees from the Global South irrespective of their intelligence levels, and possibly also invest more resources in this objective than they do currently. In fact, given our humanitarian responsibilities, the moral permissibility of denying them admission could even depend on whether their resettlement in a safe country within the Global South is supported, which is an important topic for future research.

Funding

This research received no external funding.

Acknowledgments

I have several people to thank—you know who you are.

Conflicts of Interest

The author declares no conflict of interest.

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1
In this article, I use ‘IQ,’ ‘cognitive abilities,’ and ‘intelligence’ interchangeably. While there are subtle distinctions among these terms, they are not significant for the purposes of my main argument.
2
Of course, insofar as one believes that cosmopolitan principles entail an unconditional right to freedom of movement, then even under the conditions described, states would still be duty-bound to admit the refugees in question. Although a discussion of this topic is beyond this article’s scope, suffice it to say that I do not believe that such a right is plausible even from a cosmopolitan perspective. Alternatively, some might defend the large-scale admission of refugees from the Global South irrespective of their intelligence levels on the grounds that current attempts to exclude them inflict harm, rather than merely allow it to happen. I will consider this argument in the final section.
3
Incidentally, the cultural explanation for East Asian and Ashkenazi Jewish success is also generally accepted by those who attribute the Black–White IQ gap solely to discrimination and racism. Rejecting this explanation as an environmentalist would imply that academic and economic institutions are skewed against white people in favor of East Asians and Ashkenazi Jews – suggesting that we live in East Asian- or Jewish-supremacist societies, which appears to contradict influential anti-white narratives (cf. Pluckrose & Lindsay, 2020).
4
In this survey, which was conducted in 2013–2014 among those who were either members of the International Society for Intelligence Research (ISIR) or had published at least one post-2010 paper in Intelligence, Cognitive Psychology, Contemporary Educational Psychology, New Ideas in Psychology, or Learning and Individual Differences, 90% (N = 71) asserted that genes exert at least some influence on cross-national differences in cognitive ability (Rindermann et al., 2016). Additionally, 60% (N = 86) claimed believing that the Black–White IQ gap in the US was at least 50% genetically caused, with 43% favoring a greater role for genes than for environmental factors (Rindermann et al., 2020).
5
See also Hawks et al. (2007) and Akbari et al. (2024) for evidence that human evolution has accelerated during this period.
6
This is reflected in Jewish scholarly accomplishments. Almost 24% of Nobel Prize winners in medicine and science have been Jewish even though Jews represent only 0.2% of the world population, with American Jews taking 37% of all US awards in these fields despite comprising a mere 2% of the US population (Gerstl, 2020).
7
It is also worth observing that if Rinderman, Klauk, and Thompson are right that recent refugees in Germany from the Global South have IQs approximately 5–10 points higher than those in their home countries, then their children (but not subsequent generations, as regression to the mean does not continue indefinitely – if it did, evolution would not be possible) are likely to have lower genetic intelligence than their parents due to regression toward the population mean, which occurs because of the low probability that parents will pass on all of their exceptional genes to their children (Jensen, 1973; Rushton & Jensen, 2008). However, since the impact this has on the children's IQ could be partially or even fully mitigated by the generally superior environmental conditions in the Global North compared to the Global South, such as better education and nutrition, I do not wish to place too much emphasis on this point.
8
An anonymous reviewer has suggested to me that residents of the Global North might gain certain cultural benefits from migration from the Global South, including low-skilled migration. While I agree with this – I, for one, enjoy living in a city with diverse restaurants and cultural festivals, and know many others who do too – it is hard to believe that these benefits would fully compensate for the economic costs alone. If studies like Van De Beek’s, which estimate that non-Western immigrants in the Netherlands cost the public on average €275,000 per person, are even broadly accurate, then the financial burdens imposed seem to vastly outweigh such cultural benefits. Moreover, once the number of individuals from a particular cultural or ethnic background reaches a certain threshold – perhaps enough to support ethnic restaurants and cultural festivals in every major city or to facilitate personal connections that provide exposure to diverse cultural practices and ways of life – it looks like the marginal cultural benefits for the host population will decline.
9
Indeed, since intelligence – shown earlier to be strongly influenced by genetics – is positively correlated with saving rates, social cooperation, and support for economic freedoms (e.g., Benjamin et al., 2013; Carl, 2014; Jones, 2016; Proto et al., 2019; Warner & Pleeter, 2001), Jones’ cultural transplant effects could be partially mediated by possible genetic differences in intelligence between ethnic and racial groups (see Section 3.1), even if they cannot be reduced to them.
10
Of course, since the Global South will likely continue producing refugees, a further question that would arise is whether future refugees from this region could also be accommodated without significantly harming global innovation.
11
Admittedly, achieving this may be difficult within the European Union. This is because the Union’s internal freedom of movement allows refugees, once they obtain a residence permit, to relocate to any member state, and the countries that have proven the most popular destinations for such secondary migration – Germany, France, the Nordic states, and the Low Countries – are also those most important from a global innovation perspective (Wagner et al., 2019).