Evidence of correlations between human partners based on systematic reviews and meta-analyses of 22 traits and UK Biobank analysis of 133 traits

Abstract

Positive correlations between mates can increase trait variation and prevalence, as well as bias estimates from genetically informed study designs. While past studies of similarity between human mating partners have largely found evidence of positive correlations, to our knowledge, no formal meta-analysis has examined human partner correlations across multiple categories of traits. Thus, we conducted systematic reviews and random-effects meta-analyses of human male-female partner correlations across 22 traits commonly studied by psychologists, economists, sociologists, anthropologists, epidemiologists and geneticists. Using ScienceDirect, PubMed and Google Scholar, we incorporated 480 partner correlations from 199 peer-reviewed studies of co-parents, engaged pairs, married pairs and/or cohabitating pairs that were published on or before 16 August 2022. We also calculated 133 trait correlations using up to 79,074 male-female couples in the UK Biobank (UKB). Estimates of the 22 mean meta-analysed correlations ranged from r_meta = 0.08 (adjusted 95% CI = 0.03, 0.13) for extraversion to r_meta = 0.58 (adjusted 95% CI = 0.50, 0.64) for political values, with funnel plots showing little evidence of publication bias across traits. The 133 UKB correlations ranged from r_UKB = -0.18 (adjusted 95% CI = -0.20, -0.16) for chronotype (being a 'morning' or 'evening' person) to r_UKB = 0.87 (adjusted 95% CI = 0.86, 0.87) for birth year. Across analyses, political and religious attitudes, educational attainment and some substance use traits showed the highest correlations, while psychological (that is, psychiatric/personality) and anthropometric traits generally yielded lower but positive correlations. We observed high levels of between-sample heterogeneity for most meta-analysed traits, probably because of both systematic differences between samples and true differences in partner correlations across populations.

Extended Data Fig. 1. Funnel plots for each meta-analyzed trait

The funnel plots in Extended Data Fig. 1a Smoking Status, Extended Data Fig. 1b Height, Extended Data Fig. 1c Smoking Quantity, Extended Data Fig. 1d Extraversion, Extended Data Fig. 1e Neuroticism, Extended Data Fig. 1f Openness, Extended Data Fig. 1g Conscientiousness, Extended Data Fig. 1h Drinking Quantity, Extended Data Fig. 1i Agreeableness, Extended Data Fig. 1j Intelligence Quotient, Extended Data Fig. 1k Waist-to-Hip Ratio, Extended Data Fig. 1l Educational Attainment, Extended Data Fig. 1m Depression, Extended Data Fig. 1n Diabetes, Extended Data Fig. 1o Generalized Anxiety, Extended Data Fig. 1p Political Values, Extended Data Fig. 1q Religiosity, Extended Data Fig. 1r Smoking Initiation, Extended Data Fig. 1s Smoking Cessation, Extended Data Fig. 1t Problematic Alcohol Use, Extended Data Fig. 1u Substance Use Disorder, and Extended Data Fig. 1v Body Mass Index are designed to assess possible publication bias for each meta-analysis. Here, the Fisher Z-transformed correlations are plotted against their respective standard errors. For dichotomous traits, standard error was estimated using the delta method (see main text).

Extended Data Fig. 2. Partner correlations and Bonferroni-Adjusted 95% confidence intervals for 133 traits in the UK Biobank

The visualized traits represent partner correlations for all of the adequately-powered UK Biobank traits (out of an original 140). Each estimate is color-coded by the correlation type— Pearson (in blue), Spearman (in red), and Tetrachoric (in green), used for continuous, ordinal, and binary traits, respectively—with the lines depicting the Bonferroni-adjusted 95% confidence interval for each trait. Estimates are based on up to 79,074 pairs; Supplementary Table 4 includes the precise sample size for each trait along with the Bonferroni-adjusted p-values associated with the adjusted 95% confidence intervals depicted in this figure. See main text for description of specific analyses. Num Dep Episodes = Number of Depressive Episodes; Heel BMD = Heel Bone Mineral Density (in the form of a t-score); LDL = Direct Low-density Lipoprotein Cholesterol, CRP = C-reactive Protein; RBC = Red Blood Cell (Erythrocyte) Count; DBP = Diastolic Blood Pressure; CPD (All Participants) = Cigarettes per Day (Includes Current, Former, and Never Smokers); FEV1 Pred % = Forced Expiratory Volume in 1-Second (FEV1), Predicted Percentage; PEF= Peak Expiratory Flow; WBC = White Blood Cell (Leukocyte) Count; SBP = Systolic Blood Pressure; HDL = High-density Lipoprotein Cholesterol; CPD (Smokers Only) = Cigarettes per Day (Restricted to Current or Former Smokers); WHR = Waist-to-hip Ratio; BMR = Basal Metabolic Rate; FIQ = Fluid Intelligence Quotient; BMI = Body Mass Index; FVC = Forced Vital Capacity; Time to First Cig = Time to First Cigarette; EA = Educational Attainment.

Figure 1:. The point estimates of the mean meta-analyzed random effects partner correlations and UK Biobank partner correlations for comparable traits, along with their respective Bonferroni-adjusted 95% confidence intervals.

The dark blue points represent the random effects estimates of the mean meta-analyzed correlations for partners, while the red points on the same vertical axis represent the point estimates of the partner correlations for a comparable trait in the UK Biobank, where applicable. To account for multiple testing, meta-analyzed and UK Biobank correlations are shown with Bonferroni-adjusted 95% confidence intervals (adjusting for 22 and 133 traits, respectively). Table 1 and Supplementary Table 4 include the precise sample size and point estimate/adjusted confidence interval/adjusted p-value, etc. for each of these traits in the meta-analysis and UK Biobank, respectively.

Figure 2:. The UK Biobank partner correlation point estimates for 133 traits, along with their respective Bonferroni-adjusted 95% confidence intervals, grouped by category of the trait.

The point estimates on the y-axis represent the estimated partner correlation—along with Bonferroni-adjusted 95% confidence intervals (adjusting for 133 traits)--for the corresponding trait on the x-axis. Estimates are based on up to 79,074 pairs; Supplementary Table 4 includes the precise sample size/point estimate for each trait along with the Bonferroni-adjusted p-values associated with the adjusted 95% confidence intervals depicted in this figure. Traits are grouped according to six categories: health-related, psychological, demographic/family, substance use, anthropometric, and behavioral. Points representing partner correlations for continuous traits (Pearson correlations) are blue; points representing partner correlations for ordinally-coded traits (Spearman correlations) are red; points representing partner correlations for dichotomously-coded traits (Tetrachoric correlations) are light green. Num Dep Episodes = Number of Depressive Episodes; Heel BMD = Heel Bone Mineral Density (in the form of a t-score); LDL = Direct Low-density Lipoprotein Cholesterol, CRP = C-reactive Protein; RBC = Red Blood Cell (Erythrocyte) Count; DBP = Diastolic Blood Pressure; CPD (All Participants) = Cigarettes per Day (Includes Current, Former, and Never Smokers); FEV1 Pred % = Forced Expiratory Volume in 1-Second (FEV1), Predicted Percentage; PEF = Peak Expiratory Flow; WBC = White Blood Cell (Leukocyte) Count; SBP = Systolic Blood Pressure; HDL = High-density Lipoprotein Cholesterol; CPD (Smokers Only) = Cigarettes per Day (Restricted to Current or Former Smokers); WHR = Waist-to-hip Ratio; BMR = Basal Metabolic Rate; FIQ = Fluid Intelligence Quotient; BMI = Body Mass Index; FVC = Forced Vital Capacity; Time to First Cig = Time to First Cigarette; EA = Educational Attainment.