The analysis has shed unique light on the childhood predictors of inner peace. As indicated above, this outcome has received relatively little attention per se, with low arousal emotions in generally being understudied and underappreciated in research on flourishing and its various aspects. It is thus unsurprising that there has been barely any research into its childhood predictors, hence the value of our study. In summary, all three of our main hypotheses were supported, often strikingly so. As a reminder, our first was that among the 13 childhood predictors, certain ones will show meaningful associations with inner peace in adulthood. Indeed, every predictor – with the sole but striking exception of immigration status – had a significant association with inner peace when meta-analyzed over the 22 countries. Second, the strength of associations between the predictors and inner peace in adulthood will vary by country, reflecting the influence of diverse sociocultural, economic, and health contexts that characterize each nation. Third, some of the observed associations between the predictors and an individual's inner peace in adulthood will be robust against potential unmeasured confounding (as assessed through E-values). Here we shall touch in turn on the predictors, beginning with the one with the strongest impact, namely self-rated health growing up. We discuss this factor in some detail as a way of illustrating the nature and nuances of the data. We then consider the other factors more briefly, referencing and extrapolating the points made in relation to health.
Overall, the most impactful factor on average was self-rated health growing up, as assessed on a five-point scale: poor; fair; good; very good; and excellent. Relative to the middle category of “good,” the Risk Ratios (RRs) range from 0.93 for poor (95% CI [0.88, 0.99]) and 0.94 for fair (95% CI [0.91, 0.98]), to 1.04 for very good (95% CI [1.02, 1.06]) to 1.07 for excellent (95% CI [1.04, 1.11]), with all results significant at the p < 0.001 level. An RR can be interpreted as the relative percentage in each category, which in the present paper is calculated in relation to the proportion of people reporting experiencing inner peace. In that respect, although peace was assessed on a four-point scale – never, rarely, often, or always at peace – in our analysis and interpretation we aggregate this into two binary categories, whereby people either have inner peace (endorsing either “often” or “always” on the peace item) or do not have it (endorsing either “rarely” or “never”). Thus, taking the RR of 1.07 (95% CI [1.04, 1.11]) for excellent health as an example, this means that, compared to people who reported that they “only” had good health growing up, the proportion of people with excellent health who have inner peace is 1.07 times greater than those who do not have inner peace. Put another way, there is a 7% increase in having inner peace for those who reported excellent health in childhood relative to those who reported good health (conditional on all other variables in the model). Although this effect size is modest, at the population level it is quite meaningful, and moreover, in some countries the effect size was considerably higher.
One can also examine the robustness of these associations through their E-value56, which pertains to our third main hypothesis. An E-value measures the strength that an “unmeasured confounder” – a variable not included in the analyses – would need to be to “explain away” the observed relationship. In the case of excellent health, the E-value for the estimate was 1.36. This would mean an unmeasured confounder would need to be both, (a) related to peace with a RR of 1.36 (meaning that being one unit higher on the confounder is associated with a 36% increase in having peace), and (b) simultaneously related to childhood health with a RR of 1.36 (where a one unit increase on the confounder is associated with a 36% increase in being in the excellent health category over the good category). It is this simultaneous association of the unmeasured confounder with our outcome (peace) and our predictor (health) that makes the unknown variable a “confounder.” The usefulness of the E-value is that it serves as a benchmark for thinking – in light of existing knowledge and theory – about whether a confounder could exist that does indeed fulfil this criterion of simultaneous association with responses to the health and peace items. Essentially, the closer the E-value to 1, the more likely it is that such a confounder could indeed exist. Conversely, the higher the E-value, the less likely that it does. In the present case, an E-value of 1.36 is judged as high: especially given observed associations, it may be difficult to envisage an unmeasured variable that could plausibly have an RR of 1.36 with both inner peace and childhood health. That is, this RR would need to both be, (a) much higher than the one observed between excellent childhood health and inner peace (i.e., 1.07), and (b) apply separately to both childhood health and inner peace. So, in terms of our third hypothesis, we have some evidence that the observed RR between inner peace and childhood health is robust to potential unmeasured confounding, so is a “real” effect (i.e., rather than a statistical artefact produced by us not including enough relevant variables in our analysis).
This finding that childhood health is associated with inner peace in adulthood is unique: we could find no previous study that has explored such a connection, so simply observing it here is a notable addition to the literature. However, it is worth emphasizing up front a caveat, namely that we did not actually assess people’s health in childhood itself, but rather their retrospective recollections about their childhood. Crucially, there are indications that people sometimes change their ratings of childhood health over time; one analysis found nearly one half of their sample revised this during a 10-year observation period. Older adults who were relatively advantaged (e.g., with socioeconomic resources and better memory) were less likely to revise it, whereas those with multiple childhood health problems were more likely to (either positively or negatively)59. As such, we must be somewhat cautious in interpreting our data, given we did not measure health in childhood per se, and recall bias might be present. However, for recall bias to completely explain the observed associations of the childhood predictors with adult inner peace, the effect of adult inner peace on the retrospective assessments of the childhood predictors would have to be at least as strong as the observed associations themselves60.
Moroever, numerous longitudinal studies have actually measured health in childhood then traced its impact on later outcomes, with a substantial literature showing it does have a substantive effect on myriad aspects of adult life. Given that context, it is reasonable to think – based on our data – that inner peace is indeed one of the variables affected by it. Much of this existing longitudinal work focuses either on physical health or socio-economic status, with poor childhood health having a long-term detrimental health on these outcomes61,62. However, there is some work with more direct relevance to inner peace, with various studies connecting poor childhood health to mental health issues specifically in later life, particularly depression. A study involving a nationally representative sample of late midlife adults in the US, for example, found childhood disability was significantly associated with higher levels of depressive symptoms, suggesting such people may accumulate more physical impairment over the life course, thus suffering worse mental health in late midlife63. Similarly, another study found people with childhood disability exhibited more depressive symptoms at age 50 compared to those who did not, although there was no difference in the progression of depressive symptoms over time between the two groups, suggesting an initial inequality which was then maintained over the life course64.
Let us now turn to our second hypothesis, namely that we would observe national differences in the effects of the factors. Many of the studies cited above were in a US context, which indeed is characteristic of the psychological literature as a whole, as elucidated in the introduction. Thus, a particular strength of our research is its multinational reach, covering 22 diverse countries. And, as per our second hypothesis, there was indeed considerable variation in the impact of childhood health. The following are the respective RRs for the four health categories (relative to the middle category of “good”) for the 22 countries (with details for each country provided in the Supplementary Tables), together with the respective E-values, followed by 95% CIs, in square parentheses: Argentina (poor = 0.89 [1.50; 0.72, 1.09], fair = 1.12 [1.48; 1.02, 1.22], very good = 1.01 [1.08; 0.94, 1.07], excellent = 0.99 [1.12; 0.93, 1.05]); Australia (0.88 [1.54; 0.72, 1.07], 0.96 [1.27; 0.84, 1.09], 1.03 [1.21; 0.96, 1.11], 1.09 [1.41; 1.02, 1.17]); Brazil (0.99 [1.12; 0.86, 1.13], 0.93 [1.36; 0.87, 1.00], 1.07 [1.34; 1.02, 1.12], 1.14 [1.53; 1.09, 1.18]); Egypt (0.94 [1.33; 0.84, 1.05], 0.95 [1.29; 0.88, 1.02], 0.97 [1.22; 0.92, 1.02], 0.98 [1.16; 0.94, 1.03]); Germany (1.06 [1.32; 0.94, 1.20], 0.88 [1.55; 0.81, 0.95], 1.06 [1.31; 1.02, 1.10], 1.10 [1.44; 1.06, 1.15]); Hong Kong (0.73 [2.09; 0.57, 0.92], 0.85 [1.63; 0.79, 0.91], 1.04 [1.23; 1.00, 1.08], 1.03 [1.22; 0.97, 1.10]); India (0.93 [1.36; 0.84, 1.03], 0.87 [1.57; 0.82, 0.92], 0.97 [1.20; 0.93, 1.02], 1.05 [1.27; 0.99, 1.11]); Indonesia (0.76 [1.96; 0.53, 1.08], 0.97 [1.20; 0.92, 1.03], 0.99 [1.11; 0.94, 1.04], 1.02 [1.18; 0.97, 1.08]); Israel (1.02 [1.16; 0.74, 1.42], 0.89 [1.51; 0.75, 1.04], 0.96 [1.24; 0.91, 1.02], 0.98 [1.15; 0.93, 1.04]); Japan (0.75 [2.00; 0.68, 0.83], 0.86 [1.61; 0.82, 0.90], 1.12 [1.49; 1.09, 1.15], 1.20 [1.70; 1.17, 1.24]); Kenya (1.03 [1.19; 0.90, 1.17], 0.96 [1.27; 0.89, 1.02], 1.02 [1.15; 0.96, 1.08], 1.04 [1.24; 0.99, 1.09]); Mexico (0.91 [1.43; 0.75, 1.10], 1.09 [1.39; 1.01, 1.17], 0.97 [1.20; 0.91, 1.04], 0.95 [1.28; 0.90, 1.01]); Nigeria (1.19 [1.67; 1.08, 1.31], 1.03 [1.21; 0.92, 1.15], 1.04 [1.25; 0.98, 1.10], 1.01 [1.14; 0.96, 1.08]); Philippines (1.01 [1.11; 0.86, 1.18], 0.96 [1.25; 0.87, 1.05], 1.09 [1.40; 0.98, 1.21], 1.17 [1.62; 1.08, 1.27]); Poland (1.03 [1.21; 0.81, 1.32], 0.88 [1.55; 0.77, 1.00], 1.00 [1.03; 0.96, 1.05], 1.05 [1.25; 1.00, 1.11]); South Africa (0.90 [1.47; 0.78, 1.04], 0.94 [1.33; 0.84, 1.04], 1.03 [1.22; 0.95, 1.12], 0.99 [1.09; 0.93, 1.06]); Spain (1.06 [1.32; 0.86, 1.31], 0.96 [1.23; 0.79, 1.18], 0.97 [1.22; 0.89, 1.05], 0.98 [1.17; 0.90, 1.07]); Sweden (0.80 [1.82; 0.71, 0.90], 0.92 [1.40; 0.86, 0.97], 1.15 [1.56; 1.11, 1.18], 1.19 [1.68; 1.16, 1.23]); Tanzania (0.98 [1.18; 0.86, 1.11], 1.08 [1.38; 1.01, 1.16], 1.10 [1.43; 1.04, 1.17], 1.11 [1.46; 1.05, 1.17]); Türkiye (0.37 [4.82; 0.18, 0.77], 0.96 [1.25; 0.76, 1.21], 1.12 [1.48; 0.94, 1.33], 1.32 [1.97; 1.12, 1.57]); United Kingdom (0.87 [1.57; 0.69, 1.10], 0.84 [1.65; 0.73, 0.98], 1.11 [1.47; 1.03, 1.20], 1.14 [1.55; 1.06, 1.23]); and United States (0.97 [1.20; 0.78, 1.21], 0.89 [1.49; 0.79, 1.01], 1.10 [1.43; 1.04, 1.16], 1.16 [1.58; 1.10, 1.21]). As one can see, there are many notable country-level nuances. For a start, compared to the overall RR range of 0.14 (spanning 0.93 for poor to 1.07 for excellent health), some nations had a much larger range – as much as 0.95 in Türkiye – implying that childhood health is a much more significant factor there compared to other countries. More research is needed to explore why this regional variation exists, but it will almost certainly involve considerations such as the provision of healthcare in the various countries.
There were also intriguing patterns that are harder to explain and certainly merit further investigation, especially the fact that, in some countries, the RRs seemed ‘out of order.’ One would expect, based on the overall RRs, that relative to people with “good” childhood health, people with worse health (“poor” or “fair”) would have lower levels of peace (RR < 1.00), while people with better health (“very good” or “excellent”) would have higher levels (RR > 1.00). Indeed, seven countries did conform to this linear escalating pattern (Australia, Brazil, Hong Kong, Sweden, Türkiye, UK and USA). However, in the remaining countries, this pattern was subverted in various ways, where compared to those with good childhood health, some groups with worse health (either poor and/or fair) had higher levels of peace (RR > 1.00), while conversely others with better health (very good and/or excellent) had lower levels of peace (RR < 1.00). Consider Nigeria, for instance, where people with poor childhood health had an RR of 1.19 (95% CI [1.08, 1.31]): i.e., here, not only does poor childhood health not detract from inner peace in adulthood, the data imply it actively helps. Moreover, the E-value for this particular observation is 1.67 (while the E-value for the 95% CI is 1.38), suggesting this finding is very robust to potential confounding. We cannot know from our data why this effect is observed, i.e., what is special about Nigeria that childhood poor health seems to actually facilitate inner peace in adulthood. One could speculate that, at least in some countries, experiencing poor health in childhood either encourages or compels people to develop a certain resilience or other psychological qualities, that may give rise to inner peace. But this of course begs the question, namely what is it that is different about these countries that this effect is observed, and why are similar effects not found elsewhere. Certainly, this is something that demands more in-depth study.
Let us now consider the other variables. While we do not have the space to discuss these in comparable depth to childhood health, we can nevertheless highlight some notable patterns that merit further study. Indeed, to reiterate, every factor – apart from immigration status – had a significant effect on inner peace in adulthood. To begin with, family dynamics are very important, including having a good relationship with one’s mother (RR = 1.06; E = 1.34; 95% CI [1.03, 1.09]) and father (1.03; 1.21; 1.01, 1.06), as is having parents who were married compared to either being divorced (0.97; 1.22; 0.94, 1.00), single or never married (0.95; 1.29; 0.92, 0.99), or one or both parents having died during childhood (0.95; 1.30; 0.91, 0.99). The financial situation of the family also matters: relative to people whose families “got by,” those who “lived comfortably” fared better (1.03; 1.22; 1.02, 1.05), while people did worse whose families found it either “difficult” (0.98; 1.17; 0.96, 0.99) or “very difficult” (0.96; 1.25; 0.93, 0.99). These findings accord with a vast existing literature on the importance of these factors for wellbeing, both in childhood itself and moreover in later life. Thus, for example, with respect to the quality of relationships with parents, a considerable literature on attachment styles shows the positive impact of “secure” bonds – generally regarded as the optimal type of attachment – on mental health later in life65. So too with marriage: overall, research has consistently shown this to be beneficial for children relative to other possibilities such as divorce/separation, both during childhood itself66 and over the life course67, though one notes that in some situations – such as conflicted or abusive marriages – divorce may indeed be better option all round68. And again, with the financial aspect, research consistently finds that economic security in childhood is associated with better long term mental health prospects69. Until now, however, these factors had not been linked to inner peace in adulthood, and thus our work now extends the literature to encompass this.
Moreover, perhaps of even greater value in this study is the way it highlights national variation, showing that the impact of these factors differs considerably based on the location. Thus, the effect of having a good relationship with one’s mother ranged from (RR =) 0.89 in India (95% CI [0.79, 1.00]) to 1.26 in Indonesia (95% CI [0.99, 1.60]), while the impact of having a good relationship with one’s father ranged from 0.93 in Nigeria (95% CI [0.82, 1.05]) to 1.16 in Türkiye (95% CI [0.92, 1.45]). Likewise, there was considerable variation pertaining to parental marital status, where compared to having parents who were married, the effect of parents: being divorced ranged from 0.81 in Nigeria (95% CI [0.72, 0.91]) to 1.36 in Türkiye (95% CI [1.03, 1.80]); being single or never married ranged from 0.79 in Egypt (95% CI [0.58, 1.06]) to 1.15 in Australia (95% CI [1.01, 1.31]); and one or both parents having died ranged from 0.74 in South Africa (95% CI [0.61, 0.90]) to 1.16 in Mexico (95% CI [1.02, 1.32]) and the Philippines (95% CI [0.91,1.48]). Finally, there was also variation in relation to finances, albeit less so than the other familial dynamics, implying this factor is somewhat less susceptible to cultural influence. Thus, compared to those whose families “got by” financially, the effect of one’s family having “lived comfortably” ranged from 0.95 in Poland (95% CI [0.91, 1.00]) to 1.18 in Türkiye (95% CI [1.03, 1.34]), while for those who found it “difficult” ranged from 0.91 in Japan (95% CI [0.87, 0.95]) to 1.05 in the US (95% CI [1.00, 1.09]), and for those who found it “very difficult” ranged from 0.76 in Türkiye (95% CI [0.55, 1.07]) to 1.14 in Spain (95% CI [0.94, 1.38]). Again, these regional differences are fascinating and deserve further study, and will require in-depth enquiry into cultural dynamics to help explain them.
Consider for example the impact of having parents who were divorced, with a 0.55 RR differential between Nigeria, where such divorce has a markedly negative impact on the likelihood of experiencing peace in adulthood, and Türkiye, where it means one is more likely to have peace compared to people whose parents were married. Accounting for such findings will require detailed exploration into the traditions, values and practices pertaining to both marriage and divorce in the respective countries. It may be relevant, for instance, that Nigeria has large numbers of both Christians (45.9% of the population) and Muslims (53.5%), whereas Türkiye is overwhelmingly Muslim (99%)70. In that respect, it is possible that Islam is more accommodating of divorce – albeit still describing it as a “necessary evil”71 – than Christianity, and hence overall may be less destabilising to the future equanimity of Muslims than Christians. However, when comparing results across countries, it is also possible that subtle culturally-influenced linguistic nuances are playing a role, influencing the data. When developing translations of the original English-language scale for use in the non-English-speaking countries, Gallup used their considerable experience and expertise to ensure the translations were as accurate and comparable as possible, such that the rendering of “inner peace” in Turkish would signify the same phenomenological state as do its equivalents in the languages of Nigeria. It is nevertheless possible that these terms were not precisely equivalent, and perhaps – even if only very subtly – were actually assessing slightly different outcomes. This is not a possibility we can investigate in the present paper, and would require in depth qualitative research to explore, which indeed we hope this paper will inspire. But it is still worth bearing in mind as we seek to understand apparent differences between nations.
Another important variable is religious attendance at age 12. Not only was this associated with adult inner peace, but moreover an increasing amount depended on the frequency of attendance. So, compared to those who never attended, the impact of attending rose from RR = 1.03 for those attending less than once a month (95% CI [1.02, 1.05]), to 1.05 for those attending 1–3 times a month (95% CI [1.02, 1.08]), to 1.06 for those attending at least weekly (95% CI [1.04, 1.09]). This aligns with an extensive body of work on the positive impact of childhood religious attendance on subsequent physical and mental health72 and also with scholarship that explores the centrality of peace to many religious traditions18. Again though, our study seems to be the first to link childhood religious service attendance to inner peace specifically. Also again, however, perhaps even more striking is the regional variation, where the impact of attending less than once a month ranged from 0.84 in Nigeria (95% CI [0.67, 1.05]) to 1.17 in Türkiye (95% CI [0.94, 1.46]), of attending 1–3 times a month ranged from 0.93 in South Africa (95% CI [0.82, 1.05]) to 1.32 in Türkiye (95% CI [1.08, 1.61]), and attending weekly ranged from 0.92 in Nigeria (95% CI [0.79, 1.07]) to 1.33 in Türkiye (95% CI [1.12, 1.57]). Thus, we see a striking comparison between – as above – Nigeria and Turkey in particular, where childhood religious attendance in the former seems potentially detrimental to adult inner peace, while in the latter it strongly supports this later outcome. Thus, as with all factors here, the impact of attendance may not be uniformly positive, and depends on cultural factors. In that respect, in-depth work in places like Nigeria will help us better understand why this country in particular seems to buck the overall trend. One wonders, for example, about the relevance, as noted above, of Nigeria having two main religions – which moreover can often be in tension and even conflict with one another in the country73 – while Türkiye is nearly all Muslim, and hence lacks comparable internal divisions. It does therefore seem plausible that religious involvement in Nigeria could bring a level of adversity or friction that is mostly absent in Türkiye, thus accounting for the significant disparities in the impact of that involvement on adult inner peace.
The final set of factors that seem impactful for inner peace are adverse experiences, namely experiencing abuse and being an outsider growing up, both with an RR of 0.94 (and 95% CIs of 0.92, 0.96, and 0.91, 0.97, respectively). These of course connect with a now vast literature on the long-term detrimental impact of Adverse Childhood Experiences, which are documented to negatively impact a panoply of outcomes later in life, ranging from substance use74 and food insecurity75 to depression76 and even frailty in older adults77. Thus, to this literature we can also add that such adversities also lower the likelihood of experiencing inner peace as an adult. Again though, the regional variation is striking, where the impact of abuse ranges from 0.80 in Poland (95% CI [0.69, 0.91]) to 1.01 in Mexico (95% CI [0.95, 1.07]), while the impact of being an outsider ranges from 0.83 in Brazil (95% CI [0.78, 0.88]) to 1.07 in Türkiye (95% CI [0.87, 1.33]). Here it seems that, in certain countries, experiencing abuse or being an outsider can make it more likely one will experience peace later in life. This seems to echo the finding above regarding poor childhood health, where in select countries, like Nigeria, this raised the chances of people having inner peace in adulthood. As in that health case, it would appear that, at least in some cultural contexts, adversity can lead people to develop the aptitude or fortitude that leads to a greater propensity to attain peace later in life. Again, we cannot tell from our data what it is about these particular contexts that does perhaps enable that, but this would be a fruitful avenue for future research to investigate.
Finally, there are three factors that are not necessarily about childhood per se, but are nevertheless relevant to childhood, namely, people’s age, sex, and immigration status. In one sense of course, these are childhood factors (in that they tell us something about people’s childhood), but from another perspective they are factors that pertain to the individual at all life stages. Nevertheless, they are worth briefly noting here. Of these, age had the strongest impact. Essentially, the older the participant, the more likely they are to have inner peace. Compared to people aged 18–24 (i.e., born between 1998 and 2005), those aged 25–29 (1993–1998) had just a marginally higher RR of 1.01 (95% CI [0.99, 1.03]), but the RRs rise in a linear way with the age categories, culminating in an RR of 1.19 (95% CI [1.12, 1.27]) for people aged over 80 (born in 1943 or earlier). These findings could be regarded as reflecting a childhood factor, especially if we interpret the data as being about the time period when people were born, hence being a cohort effect. However, the emergent literature on inner peace suggests it tends to increase as a function of age30. As such, it is perhaps more realistic to interpret the findings here as simply being more a question of the actual current age of the participants. Nevertheless, it is again still interesting to note regional variation, where the RR of this oldest category ranged from 0.77 in Poland (95% CI [0.60, 1.00]) to 1.37 for the UK (95% CI [1.20, 1.56]) and US (95% CI [1.22, 1.54]), showing that the relationship between age and peace is not universally observed, and like the other factors here is affected by socio-cultural dynamics.
The penultimate variable is gender, which ranked second last in terms of impact, where compared to men, women had an RR of 0.98 (95% CI [0.96, 1.00]). That said, we should note a very small percentage of the sample stated their sex was neither male nor female but “other”, with this group having considerably lower inner peace (RR = 0.44, 95% CI [0.13, 1.50]). We do need to be cautious in interpreting this finding, as this group was very small (< 0.1% of the observed sample) within several countries, leading to complete separation and large uncertainty in this estimate. Nevertheless, it is a strikingly low RR that does demand further study. There is by now an extensive literature showing that people who identify as LGBTQ + tend to have lower levels of mental health across the lifespan, from youth78 to older adults79. It is perhaps unsurprising then that this factor then would also affect inner peace. It is not certain whether the data here constitutes a childhood factor per se, since the item asks people their current gender, not their gender as a child, and it is possible that some percentage who answered “other” now would not have done so in childhood. That said, even if the latter were the case, it is likely that some relevant dynamics may have manifested during childhood (e.g., a sense of gender dysphoria). Thus, more research will be needed to look into this finding. Also, as with other factors, it will also be important to investigate the regional variation, where the RR for females ranged from 0.90 in Kenya (95% CI [0.87, 0.93]) to 1.13 in Türkiye (95% CI [1.00, 1.27]), and for those answering “other” ranging from 0.40 in Indonesia (95% CI [0.10, 1.61]) to 1.36 in Mexico (95% CI [0.89, 1.96]). It would be helpful to know, for instance, what it is about Mexico that means people who answer “other” tend to be much more likely to have inner peace than men or women.
Lastly, there was one factor with no significant impact on peace, namely immigration status: compared to people born in the country in which they live, those born elsewhere had a RR that was basically equal (1.01, 95% CI [0.98, 1.03]). As with age and gender, this is not necessarily a childhood factor, since it reflects a person’s current immigrant status, not that of when they were a child. Nevertheless, it is still intriguing to note that such status does not seem to have any bearing on inner peace, which is notable, given that being an immigrant is frequently perceived as presenting challenges that can be detrimental to mental health80. That said, research has often found immigrant mental health is “better than expected”81, and may even be better than native people, a phenomenon remarked on often enough to have a label – the “healthy immigrant effect” – which “suggests that immigrants have a health advantage over the domestic-born,” though this usually “vanishes with increased length of residency”82. In our case, while we didn’t observe this kind of effect, neither were immigrants disadvantaged when it comes to peace. Again though, there were also significant regional disparities, with RR ranging from 0.92 in Egypt [0.69, 1.23] and India (95% CI [0.76, 1.10]) to 1.19 in Tanzania (95% CI [0.85,1.65]), so in some countries at least the healthy immigrant effect does seem to play out.