About the Authors

Kimmo Eriksson


Affiliations School of Education, Culture and Communication, Mälardalen University, Västerås, Sweden, Centre for the Study of Cultural Evolution, Stockholm University, Stockholm, Sweden

Olle Häggström

Affiliation Mathematical Statistics, Chalmers University of Technology, Göteborg, Sweden

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Analyzed the data: KE. Wrote the paper: KE OH.