Jyväskylä Longitudinal Study of Personality and Social Development was initiated as Lea Pulkkinen's doctoral dissertation in 1968. Since then, the study has continued to follow the same individuals for over 40 years. When the project was launched, 369 eight-year-old children participated in the research. They were randomly selected among second-graders in primary school. After the first research, data have been collected when the respondents have been 14, 20, 27, 33, 36, 42, and 50 years old. The latest data collection took place in 2009.
When the respondents were still in school, the principal methods of data collection were teacher ratings and peer nominations on the pupils' social behaviour. In adulthood, the data collection methods have mostly been interviews and questionnaires. At the ages of 42 and 50, the respondents also participated in medical examinations and laboratory tests. The research themes have included socioemotional development and personality, education and career, family of origin and one's own family, health behaviour and health, and social adjustment. Further information on the research and the methods used can be found for example on the website of the Department of Psychology at the University of Jyväskylä.
The number of participants has been high during the whole project: each round of data collection has yielded a response rate of 70% or more among the original sample. The sample has been proven to be representative of its age group in terms of family relations, education, occupational status, and unemployment.
The Academy of Finland has been the main source of funding since 1986. In addition, the Finnish Cultural Foundation funded the project in 1986. The research was conducted by university students and officials at the University of Jyväskylä up to 1986. The Jyväskylä Longitudinal Study of Personality and Social Development (JYLS) was one of the three major longitudinal studies included in the Human Development and Its Risk Factors Programme, which was approved as the Centre of Excellence for the years 1997-1999 and 2000-2005 by the Academy of Finland and the Ministry of Education. In 2009, the data collection was financed by the Academy of Finland's funding granted to Lea Pulkkinen (decision no. 127125) and Katja Kokko (decision no. 118316). The project is located at the Laboratory of Middle-age Development in the Department of Psychology at the University of Jyväskylä and led by Docent and Academy Researcher Katja Kokko.
The data are part of the Jyväskylä Longitudinal Study of Personality and Social Development (JYLS), in which the same individuals have been followed over 30 years. At this research stage, data were collected using a theme interview, a life situation questionnaire, and two personality tests. This dataset contains the original transcribed responses to the questions presented in the theme interview. The dataset FSD2101 Jyväskylä Longitudinal Study of Personality and Social Development (JYLS): Interviews of 27-Year-Olds 1986 includes the numerically classified responses. Topics covered housing, mobility, children, childhood memories, parents, crimes and transgressions, material and emotional support received, social life, vocational education, work, attitude towards various things, social participation, smoking, alcohol use, health, goals in life, and identity.