Data for: Greener Than Thou: People Who Protect the Environment are More Cooperative, Compete to Be Environmental, and Benefit from Reputation

Published: 24 August 2020| Version 1 | DOI: 10.17632/7hzcv8xtj3.1
Pat Barclay,
Jessica Barker


The two attached datafiles correspond to the manuscript "Greener Than Thou: People Who Protect the Environment are More Cooperative, Compete to Be Environmental, and Benefit from Reputation". There are four studies: one datafile for two online surveys with a Prisoner's Dilemma on Amazon Mechanical Turk (Studies 1-2) and another datafile for two in-lab Prisoner's Dilemma experiments with surveys at the end (Studies 3-4). The descriptions of the variables are in separate worksheets within each Excel file. The abstract for the paper is as follows: Abstract: Protecting the environment is a social dilemma: environmental protection benefits everyone but is individually costly. We propose that protecting the environment functions as a signal of one’s willingness to cooperate with others, and test several novel predictions from this hypothesis. We used a mathematical model to show that environmentalism can signal one’s cooperation because it indicates one’s valuation of others. We found support for this prediction in two online studies, and then conducted two laboratory studies to extend the idea that environmentalism signals one’s willingness to cooperate. Participants donated more to an environmental charity when donations were public than when anonymous, but they donated the most when competing to be chosen by an observer for a subsequent cooperative game. In other words, people competed to donate more to the environment. Bigger donors benefited, as they were subsequently chosen more often and received more cooperation from their partners. Partners benefited from choosing environmental donors: bigger donors cooperated more with subsequent partners, such that environmental donations were reliably informative about participants’ future cooperativeness. We compare multiple theories about why people behave environmentally (indirect reciprocity, signal of wealth, signal of cooperative intent), and find most support for our proposed theory that environmentalism functions to signal one’s cooperative intent. By understanding the function of environmental behaviour and stimulating competitive giving, we can increase people’s support for environmental and other charitable causes.



Cognitive Psychology, Social Psychology, Evolutionary Psychology, Behavioral Psychology, Experimental Economics, Cooperative Game