The Population Research Institute participates in the MIND research program of the Academy of Finland (2013-2017) with the research project Linked lives over the life course - A dyadic approach to social development. 

Register and longitudinal data

The project created the FINNFAMILY new demographic dataset using Finnish population registries. We also use data from several longitudinal studies with household-based sampling from the US and European countries,

The ongoing Fraternity Friendship Study is a prospective study of friendship and group formation. 

Research group

The research is based at the Population Research Institute (PRI) of Väestöliitto, the Finnish Family Federation. The research group includes Anna Rotkirch (PRI), Markus Jokela (Institute of Behavioural Sciences, University of Helsinki); Venla Berg (PRI), Anneli Miettinen (PRI) and Lassi Lainiala (PRI). International partners include Robin Dunbar and Tamas David-Barrett(University of Oxford), Max van Duijn (Leiden University), Michaela Kreyenfield (Max Planck Institute for Demographic Research) and David Lawson (London School of Hygiene and Tropical Medicine).


Pearce, E., J. Launay, M.van Duijn, A. Rotkirch, T. David-Barrett and R.I.M.Dunbar (2016) Singing together or apart: The effect of competitive and cooperative singing on social bonding within and between the sub-groups of a University Fraternity. Psychology of Music

Laakasuo, M., A. Rotkirch, V. Berg, and M. Jokela (2016) The company you keep: Personality and friendship characteristics. Social Psychological and Personality Science, 1-8.

David-Barrett, T., Behncke Izquierdo, I., Carney, J., Nowak, K., Launay, J., & Rotkirch, A. (2016) Life course similarities on social networking sites. Advances in Life Course Research 

Pettay, J. E., Lahdenperä, M., Rotkirch, A., & Lummaa, V. (2016). Costly reproductive competition between co-resident females in humans. Behavioral Ecology and Sociobiology, June 14. 

Tanskanen, A. O., Danielsbacka, M., Jokela, M., David-Barrett, T. & Rotkirch, A. (2016). Diluted competition? Conflicts between full and half siblings in two adult generations. Frontiers in Sociology, 31 May

Tanskanen, A. O., Danielsbacka, M., Jokela, M., & Rotkirch, A. (2016). Sibling conflicts in full- and half-sibling households in the UK. Journal of Biosocial Science, 1-17.

Danielsbacka, M., A. O. Tanskanen & A. Rotkirch (2015) The impact of genetic relatedness and emotional closeness on intergenerational relations. Journal of Marriage and Family 77(4), pp 889–907.

David-Barrett, T., A. Rotkirch, J. Carney, I. Behncke Izqueirdo, J. Krems, D. Townley, E. McDaniell, A. Byrn-Smith, and R.I.M. Dunbar (2015) Women universally favour dyadic relationships, men prefer male alliances. Plos ONE. March 16, 2015

Miettinen, A., Lainiala, L. & Rotkirch, A. (2015) Does domestic gender equality predict childbearing? Evidence from the time use study among Finnish couples. Acta Sociologica  58(2): 139-154.

Dávid-Barrett, T., Rotkirch, A., Carney, J., & Izquierdo, I. B. (2015). Mating strategies in Mozart's Figaro. Human Ethology Bulletin30(1), 83-98.

Tanskanen, A., M. Danielsbacka & A. Rotkirch (2015) More unintended injuries in half sibling than full sibling households in the UK.  Journal of Individual Differences, 36(3), pp. 177–182.

Berg, Venla & Anna Rotkirch: Faster transition to the second child in late 20th century Finland: A study of birth intervals. Finnish Yearbook of Population Research 49, 73-86.

Rotkirch, A., M. Lyons, T. David-Barrett and M.Jokela  (2014) Gratitude for help among adult friends and siblings. Evolutionary psychology 12(4): 673-686.

Tanskanen, A.O., Danielsbacka, M. & Rotkirch, A. (2014). Multipartner fertility is associated with lower grandparental investment from in-laws in FinlandAdvances in Life Course Research, 20.

Tanskanen, A.O., Jokela, M., Danielsbacka, M. & Rotkirch, A. (2014).  Grandparental effects on fertility vary by lineage in the United Kingdom. Human Nature, 25(2): 269-284.

Markus Jokela, Alexandra Alvergne, Anna Rotkirch, Ian J Rickard & Virpi Lummaa (2014) Associations between family size and offspring education depend on aspects of parental personality. Personality and Individual Differences  58,  95-100.

Tanskanen, Antti & Anna Rotkirch. The impact of grandparental investment on mothers’ fertility intentions in four European countries. Demographic Research 31.1 (2014): 1-26.

Berg, V., A. Rotkirch, H. Väisänen & M. Jokela (2013) Personality is differentially associated with planned and non-planned pregnanciesJournal of Research in Personality.

Pettay, J. E., Rotkirch, A., Courtiol, A., Jokela, M., & Lummaa, V. (2013). Effects of remarriage after widowhood on long-term fitness in a monogamous historical human population. Behavioral Ecology and Sociobiology, (1). doi:10.1007/s00265-013-1630-6