• Title: TwinLife - A genetically informative, longitudinal study about the development of social inequality
  • Principle Investigators: Prof. Dr. Martin Diewald (<>);
    Prof. Dr. Christian Kandler (since 07/2021) (<>);
    Prof. Dr. Rainer Riemann (until 07/2021) (<>);
    Prof. Dr. Frank M. Spinath (<>)
  • URL:

Please cite both the dataset (Diewald et al., 2023: TwinLife. GESIS, Cologne. ZA6701 Data file Version 7.1.0, and the reference paper (Hahn et al., 2016:

Study info

TwinLife is a 12-year representative behavior genetic study investigating the emergence and development of social inequalities over the life course.

The long-term project began in 2014 and surveys more than 4,000 pairs of twins and their families in different stages of life on a yearly basis. All of the subjects reside in Germany. Not only social, but also genetic mechanisms as well as covariations and interactions between these two factors can be examined with the help of identical and fraternal same-sex twins.

It is essential to follow families closely over several years to see how different aspects develop and change over time. TwinLife is designed to examine not only different etiological factors, but also different indicators of personal and social success or failure, in order to understand how social inequalities develop. Conditional factors include genetic predisposition and aspects of the environment in which children and youth live. In terms of outcomes, both subjective and objective information are considered. Children are born into an environment that affects them, but they also react and interact differently according to their individual characteristics, thus shaping their environment. In order to be able to examine in detail the reciprocal processes by which individual dispositions and environmental conditions influence each other, data on the relevant characteristics are collected over a period of twelve years.

Following important contextual domains are focused on in TwinLife:

1. Skill Formation and Education

1.1 Educational attainment and success - photos of school reports, self-report on school grades (current school marks, marks of highest graduation) (cer) - history of education and graduation: educational degrees, vocational training, year abroad (eca) - history of education and graduation: skipping/repeating a grade (eca) - recommendation for secondary education (eca) - desired school-leaving qualification (eca) - expected probability to attain a degree (eca) - type of education / training; current status of education / qualification (edu) - after-school job (edu) - school climate / student-teacher-interaction (edu) - pressure and stress at school (edu) - school report card (generated) (src)

1.2 Cognitive abilities - subtests matrices, series and classification (CFT-1R) (igf) - subtests matrices, series, reasoning and classification (CFT-20R) (igf) - self assessment on cognitive ability (igf)

1.3 Private tutoring / Utilization of special support - parental report: extracurricular activities (e.g., help with homework, remedial groups, leisure activites, etc.) (aas) - extracurricular activities (e.g., early music education, drawing, etc.) (eac)

1.4 Cognitive development - competence rating of social skills, oral skills, concentration ability, communications skills, mathematic ability, general knowledge (com) - interviewer rating on task orientation and oral skills following intelligence test (ctb)

1.5 Acadamic self-concept - academic self-concept: verbal and spatial skill (preschool) (asc) - academic self concept: anticipated self-perceived ability (spa) - academic self concept: general self-perceived ability (spa) - academic self concept: self-perceived ability in math and German (spa) - academic self concept: self-perceived job ability (spa)

1.6 Motivation - anticipated intrinsic motivation (imo) - intrinsic motivation for school in general (imo) - intrinsic motivation for math and German (imo) - anticipated learning motivation (imo) - learning motivation for school in general (imo) - job learning motivation (imo) - achievement motivation in school (imo) - achievement motivation in general (imo)

2. Career, Labor Market Attainment, and Welfare

2.1 Employment status of household members - educational and employment status of all household members (employment / education / vocational training / parental leave / pension) (hpr)

2.2 Employment status, current position and job-related burden - current employment (emp) - classification of occupation (emp) - occupational status (emp) - required qualification for occupation (emp) - working time (emp) - commuting (emp) - shiftwork (emp) - previous employment (emp) - perceived job security and satisfaction (emp)

2.3 Wages, income, welfare dependency - wages, income (inc) - welfare dependency (inc) - perceived income equity (inc)

2.4 Job autonomy - job autonomy (aut)

3. Political and Social Integration and Participation

3.1 Social participation - social participation: frequency of attendance in sports clubs, theatre, music groups or volunteer organizations (sop)

3.2 Political orientation and participation - political activity, political interest, party identification (pop) - right wing authoritarianism (RWA; short version) (rwa) - social dominance orientation (SDO; short version) (sdo)

3.3 Social networks - social capital of individuals, e.g., close friends, loneliness (net)

3.4 Religion - religious affiliation; church attendance; religiosity / spirituality (rel)

3.5 Cultural capital - cultural capital: reading, classical music, cultural discussion, cultural participation (cul) - cultural capital: availability of cultural property (cul) - music lessons (mus)

4. Personality and Individual Characteristics

4.1 Personality / Temperament - Ballon Analogue Risk Task (BART) (brt) - narcissism (nar) - personality measures (BIG5) (per) - risk aversion (per) - patience (per) - gambeling question (ris)

4.2 Self-esteem - self esteem (ses)

4.3 Self-regulation - self-control: gummy bear test (gex) - self-regulation: consistency of interest, self-control (srg)

4.4 Optimism - optimism (lot)

4.5 Fear of failure - fear of failure (fof)

4.6 Self-efficacy - perceived self-efficacy (sef)

4.7 Sensory-processing sensitivity - sensory-processing sensitivity (sps)

4.8 Locus of control and coping - stress regulation and coping (cis) - locus of control (loc) - stress regulation and coping (svk)

5. Subjective Perceptions of Quality of Life

5.1 Global life satisfaction - global life satisfaction (gls)

5.2 Domains of life satisfaction - domain-specific satisfaction (health, work/school, income/pocket money, leisure time, family life, partnership, friendships) (sat) - satisfaction with sibling relationship (sat)

5.3 Burden and stress - frequency of arguments with partner, frequency of arguments of parents, subjective burden and coping (bus) - interfamilial and extrafamilial: subjective evaluation of burden and stress and related coping capacities, burden and stress related to parenthood (ebi) - stress symptoms (str)

5.4 Life Goals - life goals: importance and progress (lgd)

5.5 Subjective perceptions of inequality - subjective perception of inequality in private life and in society (ugs)

5.6 Subjective social status - subjective social status (sss)

6. Physical and Psychological Health

6.1 Subjective physical health - current subjective health (she)

6.2 Objective physical health / Diagnoses - heigth, weight, bmi (bdy) - diagnoses (adults and children) (dia) - impairment caused by diseases (imp) - child's medical records U-Heft (photo or questionnaire): selected parameters from examination U1 to U9 (nbi) - Apgar-score (nbi)

6.3 Depression - depression screening (bdi)

6.4 Health-related behavior - doctor's visit (doc) - smoking (hbe) - alcohol consumption (hbe) - medication (hbe) - preventive medical checkup (hbe) - physical activies (pac)

6.5 Pregnancy - information on pregnancy and in-vitro-fertilization of the twin pregnancy (prg)

6.6 Puberty - beginning of physical and psychological changes, evaluation of changes (pub)

6.7 Sexual behavior - sexual attraction to males and females, sexual labeling, sexual behavior (seo)

6.8 Emotional impairment - worrying (emi) - depressive symptoms, lack of focus (emi)

7. Psychopathology and Deviant Behavior

7.1 Internalizing problem behavior - occurence of internalising problem behavior (e.g. headaches and nausea, nervousness, and being easily scared) (int)

7.2 Externalizing problem behavior - occurence of externalising problem behavior (e.g. being restless and easily distracted, having tantrums, lying and cheating) (ext)

7.3 Deviant and delinquent Behavior - long/short version of deviant-delinquent behaviour measure (del) - deviant behavior young children (e.g. lying/cheating, fighting with other children) (dev)

7.4 Counterproductive work behavior - withdrawal (being late at work, calling in sick) (cwb)

8. Environment

8.1 Parental behavior and involvement - involvement of (step-) parents (expectations, support, encouragement and punishment) (inv) - parenting style of mother, father, partner of father, partner of mother (parental self-report) (par) - parenting style of mother, father, partner of father, partner of mother (child report) (pas)

8.2 Sibling relationship quality - twin relationship: warmth, conflict, affection, hostility, rivalry (sre)

8.3 Quality of home environment - quality of familial environment (existence of bedtime routine, general atmosphere at home) (hoe)

8.4 Family activities - freetime and cultural activities with family members (self-report) (acc) - freetime and cultural activities with family members (parental report) (acp)

8.5 Grandparents - general information onf twins' grandparents (bpa) - existence of grandparents and frequency of meetings (gre)

8.6 Childcare and care characteristics - characteristics of childcare institution and group (cai) - childcare from age 0 to 6 (institutional childcare, private arrangements) (car) - twins in same childcare institution (cat) - kindergarten (structure, concept) (kgc) - twins in same institution or school (twt)

8.7 Media use - use of electronic media devices (time spent with, e.g., computer, internet, etc.), rules for media use (med) - smartphone-use (med)

8.8 Experiences of discrimination - discrimination on grounds of ethnic or cultural background, sex, religion, age, sexual identity, or disability, and burden of discrimination (dis) - discrimination on grounds of sexual orientation (dis)

8.9 Bullying - verbal and physical bullying experience in childhood and adolescence (bul)

8.10 Contact to other family members - contact and contact frequency to biological parents, twins, siblings not living in the household (anymore) (con) - parent living elsewhere (ple) - sibling living elsewhere (sle)

8.11 Life events - occurence and subjective evaluation of different life events (e.g., marriage, death, unemployment) (lev)

8.12 Life transitions - occurrence and subjective evaluation of important life transitions and developmental tasks (e.g. school enrolment, stays abroad, entering labor market, romantic relationships, change of social environment) (tra)

8.13 Family stresses - care burden on household level (nur)

8.14 Intentional level - intension to achieve certain life events (e.g. marriage, building a house) (ile)

8.15 Stays abroad - stays abroad (sab)

9. Saliva Sample

9.1 Saliva Sample - saliva sample (sal)

10. COVID-19

10.1 COVID-19 supplementary survey: retrospective assessment of socio-economic changes, behavior and health

  • retrospective: behavior, attitudes, stresses, and constraints during the Covid-19 pandemic (cor)
  • retrospective: health during COVID-19 pandemic (cor)
  • retrospective: socioeconomic changes (cor)
  • retrospective: COVID-19-related behavioral changes, resilience, coping (cor)
  • retrospective: perceived threat, stress and burden, psychological impairment (cor)
  • retrospective: evaluation of governmental restrictions (cor)

10.2 COVID-19 supplementary survey: current socio-economic situation, behavior and health

  • behavior, attitudes, stresses, and constraints during the Covid-19 pandemic (cov)
  • health during COVID-19 pandemic (cov)
  • socioeconomic changes (cov)
  • COVID-19-related behavioral changes, resilience, coping (cov)
  • perceived threat, stress and burden, psychological impairment (cov)
  • evaluation of governmental restrictions (cov)
  • corona survey wave identifier (cov)


The TwinLife panel combines a sequential cohort-design with an extended twin family-design (ETFD). The related surveys are conducted yearly, whereat the mode alternates between face-to-face at home, including some tests, and telephone interviews. Parts of the face-to-face surveys are conducted in parallel modes, i.e., as computer assisted or paper-and-pencil self-interviews.

The sequential cohort-design comprises four cohorts: The youngest twins in cohort 1 (birth years 2009 and 2010) are about 5 years of age at the time of the first survey in 2014 and 2015. The oldest twins in cohort 4 (birth years 1990 to 1993) are about 31 to 32 years of age at the time of the last survey in 2022 and 2023. The twins in cohorts 2 and 3 are born in the years 2003 to 2004 and 1997 to 1998, respectively. This design enables the TwinLife panel to cover an age range between 5 and 32 years with a data collection phase of 10 years. This age range covers important life-course transitions from school entry to the labor market entry phase as well as critical life stages for mating and family formation.

As part of the ETFD, in addition to the twins themselves the biological and if applicable social parents as well as the sibling that is closest in age to the twins are surveyed. Moreover, the partners of adult twins are included as well. This family perspective enables comparisons regarding different degrees of genetic similarity, and it is important to analyze the manifold influences of the family environment on the development of the twins in greater detail.

Geographic Coverage: Germany

Universe: Twins and their families (Extended Twin Family Design, ETFD): Monozygotic and dizygotic same-sex twin pairs born in the following years: 1.) 1990 and 1991, 2.) 1997, 3.) 2003 and 4.) 2009 (4 birth cohorts)

plus at least one biological parent

(+ if possible the other biological parent, step-parent(-s), one sibling and the twins' partners)

Selection Method: Twin families are drawn from local resident registers in communities with at least 5,000 inhabitants in Germany. The twin families are recognized as such if two same-sex people with the same date of birth lived in the same household. Then, it was checked whether the selected persons were twins indeed.

Mode of Data Collection: Face-to-Face data collection: Household interviews with the family via three different interview modes (CAPI, CASI, Paper-and-Pencil) plus cognitive tests, scans/photos of certificates and children's health record books. CATI data collection: Telephone interview with one family member (from second CATI wave onwards; before: telephone interview with each family member above the age of 10 that participated in the preceding Face-to-Face wave)

Survey institute: TNS Infratest / Kantar TNS (first Face-to-Face household survey, parts of the first telephone survey); infas Institut für angewandte Sozialwissenschaft (parts of the first telephone survey, second Face-to-Face household survey and subsequent survey waves)

Dates of Data Collections:

data collection 1 (F2F 1a) Sep 28, 2014 to May 28, 2015

data collection 1 (F2F 1b) Sep 16, 2015 to Apr 18, 2016

data collection 2 (CATI 1a) Nov 23, 2015 to Apr 18, 2016

data collection 2 (CATI 1b) Dec 05, 2016 to Apr 30, 2017

data collection 3 (F2F 2a) Nov 07, 2016 to Sep 29, 2017

data collection 3 (F2F 2b) Sep 04, 2017 to May 27, 2018

data collection 4 (CATI 2a) Oct 11, 2017 to May 12, 2018

data collection 4 (CATI 2b) Nov 06, 2018 to Apr 16, 2019

data collection 5 (F2F 3a) Nov 26, 2018 to July 06, 2019

data collection 5 (F2F 3b) Sep 16, 2019 to June 06, 2020

data collection 6 (CATI 3a) Oct 18, 2019 to April, 2020

data collection 6 (CATI 3b) Feb 18, 2021 to Aug 01, 2021

COVID-19 Supplementary Survey (CoV 1) Jul 24, 2020 to Nov 15, 2020

COVID-19 Supplementary Survey (CoV 2a) Nov 30, 2020 to Apr 20, 2021

COVID-19 Supplementary Survey (CoV 2b) Feb 18, 2021 to Aug 01, 2021

COVID-19 Supplementary Survey (CoV 3) Sep 25, 2021 to Dec 01, 2021

Scientific use files (current version: v7-0-0)

Data description

For a description of the structure of the TwinLife sample see the TwinLife Technical Report 03, for the method reports of the first four data collections see the TwinLife Technical Reports 05, 09, 10, and 12 at

Data files

  • Master data (ZA6701_master_v$): Includes information on the gross sample, such as consistency checked variables that are stable over time (sex, year of birth, relation to the twins, zygosity, migration background) and wave-specific variables (person type, response status) about all individuals included in TwinLife in each wave.

  • Survey data in person format with filter error adjustment (ZA6701_person_wid$_v$): There is one data set for each data collection. Each surveyed person has one data row (pid). The data collection identifier is the variable wid. The data were filter-cleaned, i.e. data were deleted if the question was not intended for a person according to the filter instructions. These datasets are documented on

  • Data of covid supplementary surveys (ZA6701_person_cov$_v$): There is one data set for each covid supplementary survey. Each surveyed person has one data row (pid). The data collection identifier is the variable cov.

  • Survey data in person format without filter error adjustment (ZA6701_person_unadj_wid$_v$): There is one data file for each F2F data collection including all variables that were at least partially collected in PAPI mode (self-administered) without filter error adjustment. It is up to the users to decide how to handle the information provided by the respondents.

  • Survey data in family format (ZA6701_family_wide_wid$_v$): There is one data set for each data collection. Each family has one data row with information of each participating person in the family being stored in separate variables/columns. Person format and family format data sets contain the same data using different structures.

  • Twin zygosity assessment (ZA6701_zygosity_v$): A data file with the information of the twin zygosity assessment in F2F 1.

  • Survey mode (ZA6701_mode_wid1_v$): A data file with information on the survey mode for each variable in F2F 1.

  • Survey weights (ZA6701_weights_v$): A data file containing the survey weights (design, non-response, and panel weights).

All data is provided with English and German variable descriptions. In Stata, these languages are included in one data set while in SPSS, these are separate data files. Variables and instruments are documented at Detailed information on the study and special features can be found at For questions regarding the content of the data, please contact <>.

Study units

Number of Units:

  • 18,108 individuals with at least one personal interview
  • 4096 families

Number of Variables:

  • 2,527 (F2F 1 [wid1] person-format)
  • 619 (CATI 1 [wid2] person-format)
  • 2,362 (F2F 2 [wid3] person-format)
  • 132 (CATI 2 [wid4] person-format)
  • 1,351 (F2F 3 [wid5] person-format)
  • 238 (CATI 3 [wid6] person-format)
  • 127 (CoV 1 [cov1/wid10] person-format)
  • 137 (CoV 2 [cov2/wid11] person-format)
  • 134 (CoV 3 [cov3/wid12] person-format)

Data access

Data can be accessed via the GESIS Data Catalogue:

Charges for downloading this data will be paid by the TwinLife project, so the use of the data is free of charge!

Note on availability: Data and documents are only released for academic research and teaching after the data depositor's written authorization. For this purpose the Gesis Data Archive obtains a written permission with specification of the user and the analysis intention. To get access to the TwinLife data, please fill in the Data Use Agreement.

  • Name: twinlife
  • Label: TwinLife
  • : 10
  • : 7713
  • : 59
  • : 3060

German Socio-economic Panel (SOEP)