Use of crowdsourced images for determining 2D:4D and relationship to pro-environmental variables.

"Declarations Ethics statementAll participants provided written, informed consent. This study was approved by the Human Research Ethics Board at a Canadian University and conducted in accordance with Tri-Council ethical guidelines. Conflict of interestThe authors declare no competing interests. Conflict of interest The authors declare no competing interests."

"Funding This research was funded by an institutional grant from [the Council for Research in the Social Sciences, Brock University] (grant to GJP) and the [Environmental Sustainability Research Centre, Brock University] (grant to JB). JB’s involvement in this research was also supported, in part, by the Canada Research Chairs Program. Finally, the financial support of the Natural Sciences and Engineering Research Council of Canada (grant to GP) and the Social Sciences and Humanities Research Council of Canada (grant to GP) is acknowledged."