In multivariate behavioral & quantitative genetics, a genetic correlation (denoted r g or r a ) is the proportion of variance that two traits share due to genetic causes, the correlation between the genetic influences on a trait and the genetic influences on a different trait estimating the degree of pleiotropy or causal overlap. A genetic correlation of 0 implies that the genetic effects on one trait are independent of the other, while a correlation of 1 implies that all of the genetic influences on the two traits are identical. The bivariate genetic correlation can be generalized to inferring genetic latent variable factors across >2 traits using factor analysis. Genetic correlation models were introduced into behavioral genetics in the 1970s-1980s.
Genetic correlations have applications in validation of GWAS results, breeding, prediction of traits, and discovering the etiology of traits & diseases.
They can be estimated using twin studies and molecular genetics. Genetic correlations have been found to be common in non-human genetics and to be broadly similar to their respective phenotypic correlations, but also in human traits. This finding of widespread pleiotropy has implications for artificial selection in agriculture, interpretation of phenotypic correlations, social inequality, attempts to use Mendelian randomization in causal inference, the understanding of the biological origins of complex traits, and the design of GWASes.
A genetic correlations is to be contrasted with environment correlations between the environments affecting two traits (eg if poor nutrition in a household caused both lower IQ and height); a genetic correlation between two traits can contribute to the observed (phenotypic) correlation between two traits, but genetic correlations can also be opposite observed phenotypic correlations if the environment correlation is sufficiently strong in the other direction, perhaps due to tradeoffs or specialization.
Genetic correlations are not the same as heritability, as it is about the overlap between the two sets of influences and not their absolute magnitude; two traits could be both highly heritable but not be genetically correlated or have small heritabilities and be completely correlated (as long as the heritabilities are non-zero).
For example, consider two traits - dark skin and black hair. These two traits may individually have a very high heritability (most of the population-level variation in the trait due to genetic differences, or in simpler terms, genetics contributes significantly to these two traits), however, they may still have a very low genetic correlation if, for instance, these two traits were being controlled by different, non-overlapping, non-linked genetic loci.
A genetic correlation between two traits will tend to produce phenotypic correlations - eg the genetic correlation between intelligence and SES or education and family SES implies that intelligence/SES will also correlate phenotypically. The phenotypic correlation will be limited by the degree of genetic correlation and also by the heritability of each trait. The expected phenotypic correlation is the bivariate heritability' and can be calculated as the square roots of the heritabilities multiplied by the genetic correlation. (Using a Plomin example, for two traits with heritabilities of 0.60 & 0.23, r g = 0.75 , and phenotypic correlation of r=0.45 the bivariate heritability would be 0.60 ⋅ 0.75 ⋅ 0.23 = 0.28 , so of the observed phenotypic correlation, 0.28/0.45 = 62% of it is due to genetics.)
Genetic correlations can arise due to:
- linkage disequilibrium (two neighboring genes tend to be inherited together, each affecting a different trait)
- biological pleiotropy (a single gene having multiple otherwise unrelated biological effects)
- mediated pleiotropy (a gene causes trait X and trait X causes trait Y).
- biases: population stratification such as ancestry or assortative mating (sometimes called "gametic phase disequilibrium"), spurious stratification such as ascertainment bias/self-selection or Berkson's paradox, or misclassification of diagnoses
Genetic correlations are scientifically useful because genetic correlations can be analyzed over time within an individual longitudinally (eg intelligence is stable over a lifetime, due to the same genetic influences - childhood genetically correlates r g = 0.62 with old age), or across studies or populations or ethnic groups/races, or across diagnoses, allowing discovery of whether different genes influence a trait over a lifetime (typically, they do not), whether different genes influence a trait in different populations due to differing local environments, whether there is disease heterogeneity across times or places or sex (particularly in psychiatric diagnoses there is uncertainty whether 1 country's 'autism' or 'schizophrenia' is the same as another's or whether diagnostic categories have shifted over time/place leading to different levels of ascertainment bias), and to what degree traits like autoimmune or psychiatric disorders or cognitive functioning meaningfully cluster due sharing a biological basis and genetic architecture (for example, reading & mathematics disability genetically correlate, consistent with the Generalist Genes Hypothesis, and these genetic correlations explain the observed phenotypic correlations or 'co-morbidity'; IQ and specific measures of cognitive performance such as verbal, spatial, and memory tasks, reaction time, long-term memory, executive function etc all show high genetic correlations as do neuroanatomical measurements, and the correlations may increase with age, with implications for the etiology & nature of intelligence). This can be an important constraint on conceptualizations of the two traits: traits which seem different phenotypically but which share a common genetic basis require an explanation for how these genes can influence both traits.
Genetic correlations can be used in GWASes by using polygenic scores or genome-wide hits for one (often more easily measured) trait to increase the prior probability of variants for a second trait; for example, since intelligence and years of education are highly genetically correlated, a GWAS for education will inherently also be a GWAS for intelligence and be able to predict variance in intelligence as well and the strongest SNP candidates can be used to increase the statistical power of a smaller GWAS, or one could do a GWAS for multiple traits jointly. Genetic correlations can also quantify the contribution of correlations <1 across datasets which might create a false "missing heritability", by estimating the extent to which differing measurement methods, racial influences, or environments create only partially overlapping sets of relevant genetic variants.
Hairless dogs have imperfect teeth; long-haired and coarse-haired animals are apt to have, as is asserted, long or many horns; pigeons with feathered feet have skin between their outer toes; pigeons with short beaks have small feet, and those with long beaks large feet. Hence if man goes on selecting, and thus augmenting any peculiarity, he will almost certainly modify unintentionally other parts of the structure, owing to the mysterious laws of correlation.
Genetic correlations are also useful in applied contexts such as plant/animal breeding by allowing substitution of more easily measured but highly genetically correlated characteristics (particularly in the case of sex-linked or binary traits under the liability-threshold model, where differences in the phenotype can rarely be observed but another highly correlated measure, perhaps an endophenotype, is available in all individuals), compensating for different environments than the breeding was carried out in, making more accurate predictions of breeding value using the multivariate breeder's equation as compared to predictions based on the univariate breeder's equation using only per-trait heritability & assuming independence of traits, and avoiding unexpected consequences by taking into consideration that artificial selection for/against trait X will also increase/decrease all traits which positively/negatively correlate with X.
Breeding experiments on genetically correlated traits can measure the extent to which correlated traits are inherently developmentally linked & response is constrained, and which can be dissociated. Some traits, such as the size of eye spots on the butterfly Bicyclus anynana can be dissociated in breeding, but other pairs, such as eye spot colors, have resisted efforts.
Genetic correlations require a genetically informative sample. They can be estimated by using breeding experiments on two traits of known heritability and selecting on one trait to measure the change in the other trait (allowing inferring the genetic correlation), family/adoption/twin studies (analyzed using SEMs or DeFries-Fulker extremes analysis), molecular estimation of relatedness such as GCTA, methods employing polygenic scores like LD score regression, BOLT-REML, CPBayes, or HESS, comparison of genome-wide SNP hits in GWASes (as a loose lower bound), and phenotypic correlations of populations with at least some related individuals. (As with estimating SNP heritability, the better computational scaling & the ability to estimate only using public polygenic scores is a particular advantage for LD score regression over competing methods, and combined with the increasing availability of polygenic scores from datasets like the UK Biobank has led to an explosion of genetic correlation research in the 2010s.) The methods are related to Haseman-Elston regression & PCGC regression. Such methods are typically genome-wide, but it is also possible to estimate genetic correlations for specific variants or genome regions.
One way to consider it is using trait X in twin 1 to predict trait Y in twin 2 for monozygotic and dizygotic twins (ie using twin 1's IQ to predict twin 2's brain volume); if this cross-correlation is larger for the more genetically-similar monozygotic twins than for the dizygotic twins, the similarity indicates that the traits are not genetically independent and there is some common genetics influencing both IQ and brain volume. (Statistical power can be boosted by using siblings as well.)
Genetic correlations are affected by methodological concerns; underestimation of heritability, such as due to assortative mating, will lead to overestimates of longitudinal genetic correlation, and moderate levels of misdiagnoses can create pseudo correlations. As they are affected by heritabilities of both traits, genetic correlations have low statistical power, especially in the presence of measurement errors biasing heritability downwards, because "estimates of genetic correlations are usually subject to rather large sampling errors and therefore seldom very precise": the standard error of an estimate r g is σ ( r g ) = 1 − r g 2 2 ⋅ σ ( h x 2 ) ⋅ σ ( h y 2 ) h x 2 ⋅ h y 2 . (Larger genetic correlations & heritabilities will be estimated more precisely.) However, inclusion of genetic correlations in an analysis of a pleiotropic trait can boost power for the same reason that multivariate regressions are more powerful than separate univariate regressions.
Twin methods have the advantage of being usable without detailed biological data, with human genetic correlations calculated as far back as the 1970s and animal/plant genetic correlations calculated in the 1930s, and require sample sizes in the hundreds for being well-powered, but they have the disadvantage of making assumptions which have been criticized, and in the case of rare traits like anorexia nervosa it may be difficult to find enough twins with a diagnosis to make meaningful cross-twin comparisons, and can only be estimated with access to the twin data; molecular genetic methods like GCTA or LD score regression have the advantage of not requiring specific degrees of relatedness and so can easily study rare traits using case-control designs, which also reduces the number of assumptions they rely on, but those methods could not be run until recently, require large sample sizes in the thousands or hundreds of thousands (to obtain precise SNP heritability estimates, see the standard error formula), may require individual-level genetic data (in the case of GCTA but not LD score regression)
Given a genetic covariance matrix, the genetic correlation is computed by standardizing this, i.e., by converting the covariance matrix to a correlation matrix. For example, if two traits, say height and weight have the following additive genetic variance-covariance matrix:
Then the genetic correlation is .55, as seen is the standardized matrix below:
In practice, structural equation modeling applications such as Mx or OpenMx (and before that, historically, LISREL) are used to calculate both the genetic covariance matrix and its standardized form. In R, cov2cor() will standardize the matrix.
Typically, published reports will provide genetic variance components that have been standardized as a proportion of total variance (for instance in an ACE twin study model standardised as a proportion of V-total = A+C+E). In this case, the metric for computing the genetic covariance (the variance within the genetic covariance matrix) is lost (because of the standardizing process), so you cannot readily estimate the genetic correlation of two traits from such published models. Multivariate models (such as the Cholesky decomposition) will, however, allow the viewer to see shared genetic effects (as opposed to the genetic correlation) by following path rules. It is important therefore to provide the unstandardised path coefficients in publications.
Genetic correlations, positive & negative, have been measured for a wide variety of human traits using primarily twin and molecular genetic methods.
facial averageness/attractivenessbaldnesstiredness/forced expiratory volumetiredness/grip strengthtiredness/self-rated healthtiredness/longevityself-reported health/longevitylife satisfaction/positive affectexercise/longevityself-reported health/forced expiratory volume in one second (FEV1)tiredness/obesitytiredness/BMIbaseline BMI/increase in BMIchronotype/BMIundersleeping/BMIoversleeping/BMImorning chronotype/BMIdifficulty sleeping/BMIdifficulty sleeping/waist circumferencedifficulty sleeping/waist-hip ratiodifficulty sleeping/neck bone mineral densitydaytime sleepiness/BMIdaytime sleepiness/self-reported sleep durationdaytime sleepiness/difficulty sleepingdaytime sleepiness/waist circumferencedaytime sleepiness/waist-hip ratiosex/sleep patternsex/sleep qualityself-reported sleep duration/birth weightself-reported sleep duration/difficulty sleepingself-reported sleep duration/neck bone mineral densitydifficulty sleeping/birth weightbreast size/BMIsweet taste perception/BMItiredness/waist-hip ratioself-reported health/BMIearly puberty/BMIage at first sex/BMIexercise/BMIexercise/waist circumferencebody fat percentage/cardiorespiratory fitness (VO2max)BMI/waist circumferencewaist-hip ratio/BMIfasting insulin/BMIfasting glucose/waist-hip ratioheart rate recovery/vagal reboundlongevity/resting heart rateexercise/resting heart rateexercise/heart rate recoveryexercise/respiratory sinus arrhythmiaambulatory heart period/respiratory sinus arrhythmiarespiration rate/respiratory sinus arrhythmiaweight/heightspousal heightbirth weight//infant head circumferencebirth weight/birth lengthbirth weight/childhood heightbirth weight/adult heightbirth weight/waist circumferencebirth weight/hip circumferencebirth weight/BMIspousal BMIbirth weight/childhood obesitybirth weight/adult obesitybirth weight/pubertal growthage at first sex/heightage at first sex/birth weightage at first sex/birth lengthearly puberty/age at first sexearly puberty/age at first birthage at first sex/age at first birthage at first sex/age at menarcheage at first sex/age at voice breakingage at first sex/age at menopauseage at first sex/number of sexual partnersage at first sex/number of children ever bornage at first sex/childlessage at first sex/happinessage at first birth/age at menarcheage at first birth/age at menopauseage at first birth/voice breakingage at first birth/polycystic ovary syndromeage at first birth/age at first sexual intercourseage at first birth/birth weightage at first birth/years of educationage at first birth/cigarettes per dayage at first birth/ever smokedage at first birth/age onset of smokingage at first birth/triglyceridesage at first birth/type 2 diabetesage at first birth/fasting insulin levelage at first birth/waist-hip ratiospousal waist-to-hip ratioage at first birth/BMIage at first birth/heightnumber of children ever born (fertility)/age at first sexual intercoursenumber of children ever born/years of educationnumber of children ever born/number of grandchildren ever bornanthropometric measurements made on the 6 major sub-populations of the Solomon Islands (Harvard Solomon Islands Project)weightsitting heightheightbiacromial diameterbicristal diameter (biiliac breadth)chest breadthfoot lengthtotal facial heightupper facial heightnose lengthnose breadthbicondylar humerus diameterwrist breadthhand breadthhand lengthbicondylar femur diameterfoot breadthhead lengthhead breadthminimum frontal diameterbizygomatic diameterbigonial diameterhead circumferenceupper arm circumferencecalf circumferencetriceps skinfold thicknesssubscapular skinfold thicknessintracranial volume/heightintracranial volume/child head circumferenceintracranial volume/birth lengthintracranial volume/birth weightbirth length/intelligencebirth weight/intelligencehead motion/BMIhead motion/waist circumferencehead motion/hypertensionhead motion/monetary delay temporal discountingcorrelations between left/right hemisphere volume, volumes/thicknesses of individual regions, white matter connectivity, correlation between volume/thickness and cognitive performance on WM/IQ tests etc, stability of brain regions over time due to stable genetics (see also brain size and intelligence)epigenetic age acceleration/diffuse plaqueepigenetic age acceleration/neuritic plaqueepigenetic age acceleration/working memorybrain atrophy/blood pulse pressuresubcortical abnormal white matter/ependymal white matterabnormal white matter/systolic blood pressureEyes Test empathy score/volume of the caudate nucleusEyes Test empathy score/volume of the putamenhead motion/default mode network connectivityintelligence longitudinal stability and consistency cognitive performance & neuroanatomical propertiesbehavioral/emotional problems in childrenintelligence/readingintelligence/longevitytiredness/verbal-numerical reasoning self-reported health/intelligenceage at first sex/intelligenceintelligence/Opennessintelligence/Conscientiousnessintelligence/Neuroticismintelligence/anxietyintelligence/socioeconomic status (SES)intelligence/verbal-numerical reasoning/processing speed/short-term memory/Trail Making testspatial reasoningCoronary artery disease/verbal-numerical reasoningStroke: ischaemic/verbal-numerical reasoningStroke: cardioembolic/verbal-numerical reasoningStroke: large vessel disease/verbal-numerical reasoningStroke: small vessel disease/verbal-numerical reasoningType 2 diabetes/verbal-numerical reasoningADHD/verbal-numerical reasoningADHD/intelligenceAlzheimer's disease/verbal-numerical reasoningAutism/verbal-numerical reasoningautism/intelligenceBipolar disorder/verbal-numerical reasoningMajor depressive disorder/verbal-numerical reasoningschizophrenia/intelligence Schizophrenia/verbal-numerical reasoningSchizophrenia/memorySchizophrenia/reaction timeSchizophrenia/educational attainmentintelligence/temperamentHippocampal volume/verbal-numerical reasoningIntracranial volume (ICV)/verbal-numerical reasoningintracranial volume/childhood cognitive functionintracranial volume/adult cognitive functionInfant head circumference/verbal-numerical reasoningInfant head circumference/intelligenceBlood pressure: diastolic/verbal-numerical reasoningBlood pressure: systolic/verbal-numerical reasoningBMI/verbal-numerical reasoningintelligence/weightHeight/verbal-numerical reasoningintelligence/heightLongevity/verbal-numerical reasoningForced expiratory volume in 1 s (FEV1)/verbal-numerical reasoningChildhood cognitive ability/verbal-numerical reasoningCoronary artery disease/reaction timeStroke: ischaemic/reaction timeStroke: cardioembolic/reaction timeStroke: large vessel disease/reaction timeStroke: small vessel disease/reaction timeType 2 diabetes/reaction timeADHD/reaction timeAlzheimer's disease/reaction timeAutism/reaction timeBipolar disorder/reaction timeMajor depressive disorder/reaction timeHippocampal volume/reaction timeIntracranial volume/reaction timeInfant head circumference/reaction timeBlood pressure: diastolic/reaction timeBlood pressure: systolic/reaction timeBMI/reaction timeHeight/reaction timeLongevity/reaction timeForced expiratory volume in 1 s (FEV1)/reaction timeChildhood cognitive ability/reaction timeCoronary artery disease/memoryStroke: ischaemic/memoryStroke: cardioembolic/memoryStroke: large vessel disease/memoryStroke: small vessel disease/memoryType 2 diabetes/memoryADHD/memoryAlzheimer's disease/memoryAutism/memoryBipolar disorder/memoryMajor depressive disorder/memoryHippocampal volume/memoryIntracranial volume/memoryInfant head circumference/memoryBlood pressure: diastolic/memoryBlood pressure: systolic/memoryBMI/memoryHeight/memoryLongevity/memoryForced expiratory volume in 1 s (FEV1)/memoryChildhood cognitive ability/memorygo-no-go/fast task reaction timeintelligence/reaction-time variabilityintelligence/reaction-timereaction-time variability/ADHDreaction-time/reaction-time variabilityfrequency of talking or texting on smartphone/intelligenceEducation
education longitudinal stabilityeducation/intelligencecollege degree/intelligenceYears of education/verbal-numerical reasoningYears of education/reaction timeYears of education/memoryHippocampal volume/educational attainmentIntracranial volume/educational attainmentInfant head circumference/educational attainmentChildhood cognitive ability/educational attainmentCollege degree/memoryCollege degree/reaction timeCollege degree/verbal-numerical reasoningintelligence/GCSE scoreseducation/family SESspousal educationeducation/SESeducation/wealtheducation/incomeeducation/welfareeducation/credit scoreseducation/social mobilityeducation/working overseaseducation/financial literacy or difficultiesage at first sex/years of educationhealth/educationbirth weight/educationself-reported health/educationeducation/self-efficacyself-efficacy/GCSE scoreschild-rated school environment/GCSE scoreseducation/personalitypersonality/GCSE scoreseducation/Opennesseducation/Conscientiousnesseducation/motivationeducation/Neuroticismeducation/Extraversionsex-specific personality effects (Aggression/Achievement Striving/Self-Control) on educationwell-being/GCSE scoreseducation/behavioral problemsparent-rated behavior problems/GCSE scoreschild-rated behavior problems/GCSE scoresindependent reading/reading ability and stabilitybook exposure/reading abilityreading fluency/reading comprehensionlongitudinal oral language/reading fluency/reading comprehensionreading/inattentionCoronary artery disease/educational attainmentStroke: ischaemic/educational attainmentStroke: cardioembolic/educational attainmentStroke: large vessel disease/educational attainmentStroke: small vessel disease/educational attainmentType 2 diabetes/educational attainmentADHD/educational attainmentADHD/GCSE exam scoresADHD/Key Stage 3 exam scoresADHD/Key Stage 5 takingAlzheimer's disease/educational attainmentAutism/educational attainmentBipolar disorder/educational attainmentMajor depressive disorder/educational attainment Blood pressure: diastolic/educational attainmentBlood pressure: systolic/educational attainmentBMI/educational attainmentwaist circumference/educationeducation/back painHeight/educational attainmentLongevity/educational attainmentForced expiratory volume in 1 s (FEV1)/educational attainmentYears of education/educational attainmentCollege degree/educational attainmentevening chronotype/educational attainmentgrades or exam scores in various school subjects arts/scienceseducational subject preferenceseducation/developmental milestones (smiling, walking, talking, feeding oneself, daytime potty training, communicating using sentences, and night-time potty training)highest level of mathematics class/college completionhighest level of mathematics class/years of educationhighest level of mathematics class/working in a technical occupationcarry a tune/highest level of mathematics classEyes Test empathy score/years of collegeEyes Test empathy score/years of educationEyes Test empathy score/intelligenceSystemizing Quotient-Revised (SQ-R)/years of collegedifficulty sleeping/years of educationeducation/home environmenteducation/school environmentintelligence/criminal victimizationfood fussiness/food neophobiadental fear/fear of paincarry a tune/clap to a beatcarry a tune/perfect pitchcarry a tune/sing back musical notesphonological coding/pig Latin taskphonological coding/rhyme-generationlongitudinal stability of planning/behavioral disinhibition (Porteus Maze Test)longitudinal stability of personalityrisk-taking behavior of various kinds (natural/physical, moral, financial, reproductive, competitive, safety, gambling)personality traitspersonality traits/psychiatric disorderspersonality traits/borderline personality disorderintellectual disabilitiesreading/math disabilityreading difficulty/sexword recognition/phonological coding/orthographic coding in the reading disabledpsychiatric illnesses/property crimeschizophrenia/epilepsyschizophrenia/bipolar disorderbipolar subtype 1/bipolar subtype 2/schizophreniaschizophrenia/brain-volumesschizophrenia/major depressive disorderearlier-onset major depressive disorder (MDD)/adult-onset MDD/schizophrenia/bipolar disorderOpenness/schizophreniaschizophrenia/autismsleep/schizophreniatiredness/schizophreniaself-reported health/schizophreniacreativity/schizophreniaage at first sex/schizophreniaschizophrenia/HIV infection/risky sexual behaviorEmpathy Quotient score/schizophreniaself-reported sleep duration/schizophreniadaytime sleepiness/schizophreniabipolar disorder/rheumatoid arthritisbipolar disorder/type 2 diabetesbipolar disorder/major depressive disorderbipolar disorder/creativityConscientiousness/bipolar disorderOpenness/bipolar disorderOpenness/major depressive disorderself-reported sleep duration/bipolar disorderage at first sex/bipolar disorderEmpathy Quotient score/bipolar disorderSystemizing Quotient-Revised (SQ-R)/bipolar disorderbrain region activation/bipolar disordertiredness/ADHDmajor depressive disorder/ADHDself-reported health/ADHDautism/ADHDExtraversion/ADHDage at first sex/autismEmpathy Quotient score/autismSystemizing Quotient-Revised (SQ-R)/autismage at first sex/ADHDADHD/ticsADHD/obsessive-compulsiveintracranial volume/ADHDADHD/bipolar disordertiredness/bipolar disordertiredness/major depressive disorderdaytime sleepiness/major depressive disorderdifficulty sleeping/major depressive disorderself-reported health/major depressive disorderschizophrenia/major depressive disorderbipolar disorder/major depressive disorderage at first sex/major depressive disordermigraine/Neuroticismtiredness/Neuroticismself-reported health/NeuroticismGrit/ConscientiousnessConscientiousness/ExtraversionNeuroticism/ExtraversionOpenness/ExtraversionExtraversion: sociability and impulsiveness facetsSocial Anxiety Score/Extraversionfrequency of talking or texting on smartphone/ExtraversionNeuroticism/ConscientiousnessOpenness/ConscientiousnessOpenness/NeuroticismAgreeableness/ConscientiousnessAgreeableness/ExtraversionAgreeableness/NeuroticismAgreeableness/major depressive disorderConscientiousness/major depressive disorderConscientiousness/autism spectrum disorderAgreeableness/autism spectrum disorderEyes Test empathy score/OpennessEyes Test empathy score/self-reported empathy (Empathy Quotient)Neuroticism, Extraversion, Psychoticism, social attitudes scale, Wilson conservatism scale longitudinal stabilityNeuroticism/lonelinessExtraversion/lonelinessExtraversion/bipolar disorderdepression symptoms/lonelinessbehavioral/emotional problems in childrenantisocial behavior/Extraversionantisocial behavior/Agreeablenessantisocial behavior/Conscientiousnessantisocial behavior/sensation seekingantisocial behavior/urgencyantisocial behavior/lack of premeditationantisocial behavior/lack of perseveranceantisocial behavior/Psychoticismantisocial behavior/novelty seekingantisocial behavior/impulsivityantisocial behavior/reward dependenceantisocial behavior/depressive symptomslongitudinal stability of antisocial symptomslongitudinal stability of depressive symptomsunipolar/bipolar depressionage at first sex/Alzheimersage at first sex/risk-taking propensityage at first sex/suffer from nervesage at first sex/irritable personalityself-reported health/anorexia nervosaage at first sex/anorexia nervosaobsessive-compulsive disorder/anorexia nervosaBipolar disorder/anorexia nervosaEyes Test empathy score/anorexia nervosaEmpathy Quotient score/anorexia nervosaSystemizing Quotient-Revised (SQ-R)/anorexia nervosaTourette syndrome/obsessive-compulsive disorderhoarding/obsessive-compulsive syndromeobsessive-compulsive disorder inventory/inventory subscales (checking, hoarding, obsessing, ordering, and washing)excessive object acquisition/difficulties discarding possessionscompulsive hoarding/ticsobsessive-compulsive syndrome/ticspanic disorder/generalised anxiety disorder/phobias/obsessive-compulsive disorder/post-traumatic stress disorderbulimia/anorexia nervosaRight temporal pole surface area/anorexia nervosaweight and shape concerns and behaviors/binge eatingobesity/binge eatingpurging/binge eatingbody dissatisfaction / weight preoccupation / binge eatingmajor depressive disorder/anorexia nervosaNeuroticism/anorexia nervosaSchizophrenia/anorexia nervosaConscientiousness/schizophreniaPsychiatric factor/anorexia nervosaYears of education/anorexia nervosaCollege attendance/anorexia nervosaExtreme BMI/anorexia nervosaBody fat percentage/anorexia nervosaOverweight/anorexia nervosaHip circumference/anorexia nervosaHDL cholesterol/anorexia nervosaPhospholipids in large HDL/anorexia nervosaConcentration of large HDL particles/anorexia nervosaTotal lipids in large HDL/anorexia nervosaCholesterol esters in large HDL/anorexia nervosaFree cholesterol in large HDL/anorexia nervosaTotal cholesterol in large HDL/anorexia nervosaFasting glucose/anorexia nervosaHOMA-Beta/anorexia nervosaFasting insulin/anorexia nervosaHOMA-IR/anorexia nervosamajor depressive disorder/bulimiaRight temporal pole surface area/major depressive disorderdementia with Lewy bodies/Alzheimersdementia with Lewy bodies/Parkinson'sAlzheimers/Parkinson'sdifficulty sleeping/Alzheimer's diseaseintracranial volume/Parkinson's diseasehippocampal volume/Alzheimer's diseaseautism/Social and Communication Disorders Checklistchildhood sexual abuse/age at first sexstressful life-events/psychotic eventsSubjective well-being / depressive symptomsSubjective well-being / NeuroticismNeuroticism/major depressive disorderDepressive symptoms / Neuroticismmenstrual symptoms/anxiety/depression/Neuroticismlife satisfaction/Neuroticismpositive affect/NeuroticismAnxiety disorders / subjective well-beingAnxiety disorders / NeuroticismAnxiety disorders / depressive symptomsAutism spectrum disorder / subjective well-beingAutism spectrum disorder / Neuroticismintracranial volume/autism spectrum disorderBipolar disorder / subjective well-beingBipolar disorder / NeuroticismBipolar disorder / depressive symptomsSchizophrenia / subjective well-beingSchizophrenia / NeuroticismSchizophrenia / depressive symptomsBMI / depressive symptomsCoronary artery disease / depressive symptomsCoronary artery disease/Neuroticismgeneral anxiety disorder/major depressive disorderburnout/major depressive orderburnout/general anxiety disordermajor depressive disorder/phobias (agoraphobia / social / animal / situational phobia)phobias/panic disorder/bulimia nervosaDrug use
lifetime use of marijuana/smokingtiredness/smoking statussugar consumption/drug useage at first sex/ever-smokerage at first sex/cigarettes per dayself-reported sleep duration/cigarettes per daydifficulty sleeping/cigarettes per daydaytime sleepiness/cigarettes per dayage at first sex/smoking at onsetalcohol consumption/alcohol dependence (sex-varying correlations)age at first sex/alcohol consumptionalcohol consumption/ventral striatum activity/ADHDEver-smoker / subjective well-beingEver-smoker / neuroticismEver-smoker / depressive symptomsSmoking/educationSmoking/intelligencequitting smoking/intelligencesmoking/alcohol drinkingsmoking/BMIalcohol drinking/educationalcoholism/divorcealcohol effects on arithmetic performance / alcohol effects on motor coordinationwillingness to drive drunk/Eysenck personality scalesexecutive function/substance abuse/substance dependency, longitudinalschizophrenia/marijuana usetiredness/HDL cholesteroltiredness/HbA1ctiredness/triglyceridesself-reported health/systolic and diastolic blood pressurebirth weight/diastolic blood pressurebirth weight/systolic blood pressurebirth weight/total cholesterolbirth weight/HDL cholesterolbirth weight/LDL cholesterolTriglycerides / subjective well-beingTriglycerides / neuroticismTriglycerides / depressive symptomsfasting insulin/triglyceridesfasting glucose/fasting triglycerideswaist-hip ratio/fasting triglyceridesfasting triglycerides/BMIHDL/triglyceridesearly puberty/fasting insulinearly puberty/lipid profilesearly puberty/bone mineral densityage at first sex/femoral neck bone mineral densityage at first sex/lumbar spine bone mineral densityage at first sex/fasting glucoseage at first sex/HDL cholesterolage at first sex/LDL cholesterolage at first sex/total cholesterolage at first sex/triglyceridesage at first sex/fasting insulinage at first sex/HbA1Cage at first sex/diastolic blood pressureage at first sex/systolic blood pressurefasting HDL/BMIsystolic blood pressure/BMIspousal systolic blood pressurewaist-hip ratio/fasting glucosewaist-hip ratio/fasting insulinwaist-hip ratio/HDLwaist-hip ratio/systolic blood pressurefasting glucose/fasting insulinfasting glucose/HDLfasting glucose/systolic blood pressurefasting insulin/HDLfasting insulin/systolic blood pressureHDL/systolic blood pressureliver enzymes/total cholesterolliver enzymes/LDL cholesterolliver enzymes/HDL cholesterolliver enzymes/triglyceridesliver enzymes/glucoseliver enzymes/insulinliver enzymes/HOMA-Bliver enzymes/HOMA-IRliver enzymes/c-reactive proteinliver enzymes/alcohol consumptioncortisol/cortisone levels in child/adolescent hairimmune disordersbreast cancer / ovarian cancer / prostate cancertiredness/type 2 diabetessleep/type 2 diabetesType 2 diabetes/hypertensionrheumatoid arthritis/hypertensionpsoriasis/type 2 diabetesbirth weight/type 2 diabetesbirth weight/2 hour glucose responsebirth weight/fasting insulinbirth weight/Hb1Acdifficulty sleeping/type 2 diabetesoversleeping/type 2 diabetesdifficulty sleeping/fasting insulindifficulty sleeping/fasting glucosedaytime sleepiness/HOMA-IRdaytime sleepiness/fasting insulindifficulty sleeping/HOMA-IRpsoriasis/BMIself-reported health/coronary artery diseasetriglycerides/coronary artery diseasebirth weight/coronary artery diseaseself-reported health/ischaemic strokeC-reactive protein/ischemic vascular diseasecoronary artery disease/LDLcoronary artery disease/HDLcoronary artery disease/BMIcoronary artery disease/systolic blood pressurecoronary artery disease/type 1 diabetesdaytime sleepiness/coronary artery diseasedifficulty sleeping/coronary artery diseasecoronary artery calcification (CAC)/coronary artery diseaseLp(a)/coronary artery diseaseLP-PLA2 activity/coronary artery diseasecarotid plaque/coronary artery diseasevWF/coronary artery diseaseFVIII/coronary artery diseaseheight/coronary artery diseaseself-reported health/type 2 diabetesrheumatoid arthritis/lupusearly puberty/type 2 diabetesearly puberty/cardiovascular diseaseearly puberty/polycystic ovary syndromeage at first sex/rheumatoid arthritisage at first sex/ulcerative colitisage at first sex/Crohn's diseaseCrohn's disease/ulcerative colitisCrohn's disease/ulcerative colitis/ankylosing spondylitis/psoriasis/coeliac diseaseself-reported sleep duration/Crohn's diseasedifficulty sleeping/Crohn's diseaseage at first sex/cardiovascular diseaseage at first sex/type 2 diabetestype 2 diabetes/Dyslipidemiatype 2 diabetes/osteoarthritistype 2 diabetes/osteoporosisChronic obstructive pulmonary disease (COPD)/pulmonary fibrosis/asthma/lung functionasthma/type 2 diabetesasthma/ADHDcardiovascular disease/type 2 diabetesesophageal adenocarcinoma/Barrett's esophagusIntracranial aneurysms/abdominal aortic aneurysms/thoracic aortic aneurysmsAllergic rhinitis/asthmaAllergic rhinitis/hypertensionAllergic rhinitis/osteoarthritisasthma/cardiovascular diseaseasthma/Dyslipidemiaasthma/hypertensionasthma/osteoarthritiscardiovascular disease/Dyslipidemiacardiovascular disease/hypertensioncardiovascular disease/osteoarthritisTrans-population
schizophreniagene expressionrheumatoid arthritistype 2 diabetesTrans-cohort
depressive symptoms: GERA/PGC, GERA/UKB, UKB/PGCneuroticism: UK Biobank (UKB) / Genetics of Personality Consortiumautism: PGC (USA)/iPSYCH (Denmark)male/female Empathy Quotient scoremale/female Systemizing Quotient-Revised (SQ-R)male/female Eyes Test empathy scoreARIC/EHR phenotype consistenciesTrans-method
custom immunochip (iChip) SNP array/standard SNP array (comparing their estimates for the Crohn's disease/ulcerative colitis genetic correlation)major depressive order: Psychiatric Genomics Consortium (PGC) clinical depression diagnosis/23andMe self-report depressionmajor depressive disorder/self-declared depressionBig Five personality traits in Genetics of Personality Consortium/23andMe cohortsself-reported height/clinically measured heightchimpanzee cognitive performance factorsegg color in cross vs pure bred chickensBatrachochytrium dendrobatidis infection/development time in Bufo spinosus toadFraxinus excelsior infection by Hymenoscyphus fraxineus: severities of crown and collar symptomsMimulus guttatusChinook salmonvarious rat/cattle/sheep/finch/amphipod/human/rhesus macaque/pig/inland garter snake/coastal garter snakepigsmice Eucalyptus melliodora foliage chemistrymale genital length/female brain size in Eastern mosquitofishhigher alcohol preference/greater fear potentiated startle in micebiomass/yield per plant/straw yield in Paspalum scrobiculatumsexual antagonism in Drosophila melanogastersize vs sugar content in tomatoes