Implementation Details ---------------------- This page describes how our lab implemented the procedures required by the official protocol for the RRR. It also describes and justifies any additions to or departures from that protocol. You can view the official protocl and the main project page for this RRR using these links: - Official Protocol: [https://osf.io/ypd78/][1] - Main RRR project page: [https://osf.io/scu2f/][2] ---------- #### Experimenters #### Gustav Tinghög: Assistant Professor in Economics, has conducted multiple experiments with similar methodology, e.g. Intuition and Cooperation Reconsidered, published in Nature (2013). Lina Koppel: Graduate student with a Master's Degree in Psychology, has conducted multiple experiments in small group settings as well as a previous replication study (RRR - Sripada et al. 2014). ---------- #### Setting/Lab/Equipment #### We will conduct the experiment in a computer lab that can hold up to 20 subjects per session. Divider walls prevent participants from viewing each other’s screens and the experimenter from viewing the participants. A photo of the lab, with one subject station set up, is available under the Files tab. ---------- #### Sample, subjects, and randomization #### **Target sample size:** We will schedule a total of 10 sessions with 16 participants in each session, for a target sample of 160 participants **Target sample demographics:** We will recruit participants from our subject pool at Linköping University. The current pool consists of 55% male subjects. 96% are undergraduate students in various fields. **Minimum sample size after exclusions:** 150 **Stopping rule(s):** If, after completing all of the scheduled testing sessions and after any exclusions, we have fewer than 75 subjects in either condition, we will schedule additional sessions of 16 participants until we have usable data from at least 75 participants in each condition. **Randomization to conditions:** Participants will be randomly assigned to conditions by the provided Qualtrics Script. **Blinding to conditions:** Participants will be instructed not to talk to each other during the experiment and not to reveal any details about the study to friends or potential subjects. **Exclusion rules:** We will be using the same exclusion rules required by the official protocol. Exclusion decisions will be made by someone blind to condition assignment. **Procedures for handling testing sessions for which the number of participants is not a multiple of 4:** We will recruit additional participants until we fill the empty spot(s). For example, if 15 participants show up for a session, we will find one extra volunteer (the hallways outside our testing location are usually filled with students so recruiting additional subjects is not usually a problem). Alternatively, if 13 subjects show up and we don't manage to find 3 extra volunteers, we will ask one subject to withdraw from the study (while keeping the show-up fee of 50 SEK) or wait for a later session. ---------- #### Software/Code #### We will be using the provided materials, including the Qualtrics scripts, and have verified that they work in our laboratory. ---------- #### Differences from the official protocol #### We will conduct our study in Swedish. Materials will be translated by our lab in Linköping (Tinghög & Koppel) and back-translated by the Gothenburg lab (Wollbrant & Myrseth) to verify accuracy. The study will also use Swedish currency of similar proportions to the original study. The show-up fee is 50 SEK (approx. 6 USD). Subjects can contribute 0 - 40 SEK to the public goods game. [1]: https://osf.io/ypd78/ [2]: https://osf.io/scu2f/