placestats

Births outside marriage vs. Interpersonal trust

Holds up after adjusting for income

Across 40 countries, Births outside marriage and Interpersonal trust rise and fall together at r = +0.26 (on a scale from −1 to +1, where 0 means no link). It holds up almost unchanged when only countries with similar income (GDP per person) are compared (r = +0.35, q = 0.015, allowing for the many pairs tested).

Comparing countries across the middle half of interpersonal trust, 21.5% to 47.2% of respondents, births outside marriage is 6.5% of live births higher at the top of that range than the bottom. Comparing only countries with similar national income, the gap is 10.9% of live births.

Link before adjusting (r)+0.261p = 0.104 · 40 countries
After adjusting for national income+0.353p = 0.028 · likely range [+0.04, +0.60]
p, allowing for regions0.094standard error 0.161 · 5 regions
Check for luck (q)0.015across 12,497 pairs

How to read these.r runs from −1 (one goes up as the other goes down) to +1 (they rise together), and 0 means no link. Adjusting for national income means comparing countries with the same GDP per person, so differences in wealth can’t explain the link. Income is used in percentage terms, since an extra $1,000 means more to a poor country than to a rich one. p is how likely a link this strong would be if there were really none. Below 0.05 means it is unlikely to be chance. Very small values are written in short form: 1.1e-32 means a decimal point followed by 31 zeros and then 11, so very close to zero. The likely range is where the true figure probably lies, and a range that crosses zero means the link could easily be chance. Countries in the same region tend to resemble each other, so the third figure allows for that, which gives a fairer p. The standard error is the typical size of the error in r. Finally, testing this many pairs means some will look strong by luck alone. A q below 0.05 means this link is unlikely to be one of those.

Births outside marriage · % of live birthslink with income -0.00 · independent
Interpersonal trust · % of respondentslink with income +0.66 · high

“Link with income” is how closely each measure tracks GDP per person across countries, from −1 to +1.

Every country as a dot

Births outside marriage · % of live births →Interpersonal trust · % of respondents →2.4%75.1%6.6%73.9%Australia: 36.5% of live births, 48.5% of respondentsAustria: 41.2% of live births, 49.8% of respondentsBelgium: 52.4% of live births, 35.7% of respondentsBulgaria: 59.6% of live births, 17.1% of respondentsCanada: 32.7% of live births, 46.7% of respondentsSwitzerland: 27.7% of live births, 58.5% of respondentsChile: 75.1% of live births, 12.9% of respondentsCyprus: 21.2% of live births, 6.6% of respondentsCzechia: 48.5% of live births, 27.3% of respondentsGermany: 33.1% of live births, 41.6% of respondentsDenmark: 54.2% of live births, 73.9% of respondentsSpain: 47.6% of live births, 41% of respondentsEstonia: 53.7% of live births, 33.9% of respondentsFinland: 46.1% of live births, 68.4% of respondentsFrance: 62.2% of live births, 26.3% of respondentsUnited Kingdom: 51.3% of live births, 43.3% of respondentsGreece: 13.8% of live births, 8.45% of respondentsCroatia: 22.8% of live births, 13.6% of respondentsHungary: 30.4% of live births, 27.2% of respondentsIreland: 38.4% of live births, 37.3% of respondentsIceland: 69.4% of live births, 62.3% of respondentsItaly: 33.8% of live births, 26.6% of respondentsJapan: 2.4% of live births, 33.7% of respondentsKorea, Rep.: 2.95% of live births, 32.9% of respondentsLithuania: 27% of live births, 31.7% of respondentsLuxembourg: 41.6% of live births, 31.4% of respondentsLatvia: 39.5% of live births, 22.2% of respondentsMexico: 70.4% of live births, 10.5% of respondentsMalta: 25.9% of live births, 21.3% of respondentsNetherlands: 53.5% of live births, 57% of respondentsNorway: 58.5% of live births, 72.1% of respondentsNew Zealand: 48.7% of live births, 56.6% of respondentsPoland: 26.4% of live births, 24.1% of respondentsPortugal: 57.9% of live births, 16.9% of respondentsRomania: 32.5% of live births, 12.1% of respondentsSlovak Republic: 40.7% of live births, 21.6% of respondentsSlovenia: 56.5% of live births, 25.3% of respondentsSweden: 55.2% of live births, 62.8% of respondentsTurkiye: 2.8% of live births, 14% of respondentsUnited States: 40.5% of live births, 37% of respondentsBGRCHECHLCYPDNKGRCISLJPNKORMEXNORTUR

best-fit line line after adjusting

Four ways to measure the link

MethodrpCountries
Standard (Pearson), not adjusted+0.2610.10440
By rank (Spearman), not adjusted+0.2410.13440
Standard (Pearson), adjusted for national income+0.3530.02840
By rank (Spearman), adjusted for national income+0.2950.06840

The rank version uses only each country’s place in line, from lowest to highest, so a few extreme countries count for less. The adjusted and unadjusted versions use the same 40 countries: those that report both measures and GDP per person. So the gap between them comes from the adjustment, not from a change in which countries are counted. Drop in the size of r after adjusting: -0.092 (a minus sign means it grew).

How solid is it?

Leaving out one country at a time, r ranges from +0.314 (without ISL) to +0.388 (without LUX). The bar above shows that range on a scale from −1 to +1, with the solid line at the full result. The single country that moves r most: ISL (-0.039).

Within each region

Countries are not separate, unrelated cases, and neighbors share a lot. A link that holds inside each region is far more believable than one that shows up only when comparing regions.

nr
Europe & Central Asia31+0.46

By income third

If the link shows up only in the richest third of countries, it is a feature of rich countries, not a general pattern.

nr
Poorest third14+0.49
Middle third13+0.17
Richest third13+0.63

By largest religious group

Countries grouped by a label they share, such as main religion, rather than by a number. Groups of fewer than twelve countries are not shown. These groups differ in income, region and history all at once. So a gap between them is a place to start asking questions, not an answer.

nr
Christians34+0.40

Without outliers (countries far outside the middle half of countries on either measure, by more than one and a half times the width of that middle half): r = +0.353 after dropping 0 countries.

Two series, one country

Both measures over the years for one country you pick. The two charts are stacked so they share only the years along the bottom.

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Over time, within countries

Everything above compares countries with each other at one moment. This section compares each country only with itself over 0years. So a link here can’t come from anything about a country that stays the same, such as its history, geography, institutions or culture.

Not enough history inside each country to look at this over time. That needs countries measured for several years in a row, and at least one of these measures is measured too rarely.

The data


% of live births
% of respondents		Years
Chile CHL75.1%12.9%2019, 2022
Mexico MEX70.4%10.5%2020, 2022
Iceland ISL69.4%62.3%2019, 2022
France FRA62.2%26.3%2020, 2022
Bulgaria BGR59.6%17.1%2020, 2022
Norway NOR58.5%72.1%2020, 2022
Portugal PRT57.9%16.9%2020, 2022
Slovenia SVN56.5%25.3%2020, 2022
Sweden SWE55.2%62.8%2020, 2022
Denmark DNK54.2%73.9%2020, 2022
Estonia EST53.7%33.9%2019, 2022
Netherlands NLD53.5%57%2020, 2022
Belgium BEL52.4%35.7%2018, 2010
United Kingdom GBR51.3%43.3%2021, 2022
New Zealand NZL48.7%56.6%2021, 2022

OECD databases as named on each indicator: PISA, Social Expenditure Database (SOCX), Income Distribution Database, Development Assistance Committee statistics, Family Database, Government at a Glance, Corporate Tax Statistics, employment and environment statistics
Haerpfer, C. et al., World Values Survey; EVS, European Values Study

Sources

Births outside marriage

Share of births outside marriage

OECD · via Our World in Data · CC BY 4.0 (OECD terms and conditions) · updated annual, except the snapshots noted per indicator

Live births to mothers who were not married at the time of the birth. A registered partnership counts as unmarried. So where couples register a partnership rather than marry, this partly measures which legal option is on offer. No "better" direction is set.

Interpersonal trust

Share agreeing that most people can be trusted

World Values Survey Association and European Values Study · via Our World in Data · Free for non-commercial use with attribution · updated irregular (survey waves, roughly every 5 years)

The share who answer "most people can be trusted" rather than "you can't be too careful". Trust in other people is the classic measure of social ties (social capital). It is only loosely linked to national income. That makes it one of the few measures here where adjusting for GDP is a real test, not a foregone result. The survey runs in waves, not every year. So data for each country are sparse and uneven, and two readings for a country may be five or more years apart.

How this was computed

Data used: most recent value in 2010-2025; values come from 2010–2022. To adjust for income, each measure is first predicted from GDP per person (in percentage terms, on a log scale) with a straight-line fit. Only what is left over is then compared. This is called a partial correlation. The line is drawn the standard way (ordinary least squares), which picks the line that comes closest to all the countries at once. The error margins allow for countries in the same region resembling each other, using 5 World Bank regions. The q-value corrects for testing all 12,497 pairs at once, using the Benjamini–Hochberg method. Underlying data last updated DYB 2024. How the country data works · explore Births outside marriage and Interpersonal trust

This page shows that two measures go together. It does not show that Births outside marriage changes Interpersonal trust, or the reverse. These figures also describe countries, not individual people. See the ecological fallacy.

More links with Births outside marriage or Interpersonal trust