# Pilot for Inequality and the scale of competition Prior to launching the full study, we will run a 200-participant pilot of the study to evaluate any problems with delivery, comprehension, data collection, and payment. The design will be the same; we will randomly assign the participants to the six conditions. # Second pilot modifications After the first pilot test, it came to light that our instrument included potentially framing language. Specifically, it offered respondents the choice between "share" and "fight". In the revised instrument (see component: [Survey Instrument.json](https://osf.io/tk2wm/) and [Survey Instrument.pdf](https://osf.io/v5mx6/)), we have replaced this language with more "neutral" terms ("Option 1" and "Option 2"). Relatedly, we de-italicized the word "lose" because we were concerned that it may have introduced a demand characteristic (overemphasizing loss in the hawk-hawk cell). To ensure respondent understanding, an additional comprehension question was added. The question asks respondents "How many points do you need in order to be paid $0.50?" In the instructions, we also made it clear to participants that they cannot communicate with their partners by adding the phrase "You will not be able to communicate with Person A at any point during this study." Finally, we made minor edits to ensure that each condition used identical phrasing except where the relevant variables (scale of competition and inequality) were manipulated. We will run a second 200-participant pilot of the study using the revised instrument. The details of the second pilot are otherwise identical to the first. # Third pilot modifications Review of the second pilot suggests that participants are still struggling to comprehend the goal of the task. Prior work (West et al., 2006) made the goal more explicit to the participants than we have, using the phrase "To emphasise, the broad aim of the game is to score as many points as possible, with the money given out to those that do so, as will be explained." We have decided to adopt similar language to make this clearer. In the instructions, we have inserted, in bold, the phrase "Your goal should be to earn as many points as possible, with bonuses given out to those that do so, as will be explained." Furthermore, to test comprehension and to encourage strategic thinking, we have asked participants (prior to making their decision) "What option do you think Person A will choose?", with options 1 and 2 as the possible choices. They are then asked "Now, please choose your option:", again with options 1 and 2 as the possible choices. Reference: West, S. A., Gardner, A., Shuker, D. M., Reynolds, T., Burton-Chellow, M., Sykes, E. M., … Griffin, A. S. (2006). Cooperation and the scale of competition in humans. Current Biology, 16, 1103–1106. ## Fourth Pilot Modifications In the third pilot we noticed that respondents largely believed that their partner would choose to option 1, even when it would be clearly advantageous for the partner to choose to option 2. In investigating this, we realized that the comprehension questions we asked when explaining the game did not suficiently require that respondents understand the relative disparity in points that would arise from a given outcome. For example, we asked respondents if they understood how many points they would recieve if they chose to Option 2 and their partner chose to Option 1. We did not ask if respondents understood how many points they would recieve *relative* to their partner for the same outcome. In a labratory setting, these consequences would be more clearly explained by the researcher, and the researcher would be better equipped to ensure that respondents understood these consequences. In response to this realization, and to better ensure that respondents understand the consequences of a given outcome in the context of both global and local competition, we have added four new comprehension questions. These ask respondents to identify, for each possible outcome, whether they will recieve the same, more or less points as their partner. The updated version of this survey can be found as suffixed `_r2` in the files section. They can be accessed here: [Survey Instrument R2 (PDF)](https://osf.io/b38yj/) and [Survey Instrument R2 (JSON)](https://osf.io/64vyp/) ## Fifth pilot modifications After the fourth pilot, we have decided that the inclusion of a bonus payout for ties might persuade players to be more inclined toward cooperation. To resolve this, we have modified instructions so that players are told that ties will not qualify for a bonus. We have also removed a comprehension question related to this phrase. According to the new instructions, the potential bonus schedule is binary (\\$0 or \\$1). This brings the instructions more in line with the conditions described in the model, where the payoff of a breeding vacancy is binary—either a player gains the vacancy or she does not. We also made it clear that the task is one-shot, by adding the phrase "and you will only perform this task one time." New versions of the instrument are suffixed `_r3` and are located here: [Survey Instrument R3 (PDF)](https://osf.io/gsrfx/) and [Survey Instrument R3 (JSON)](https://osf.io/dcwht/) ## Update 02-24-2016 At the conclusion of the fifth pilot, we have finalized the instrument design and are proceeding to a full round of data collection with a target of 1200 respondents. It should be noted that, in the process of conducting the pilots, we have noticed that the randomization of treatment assignments is rudamentary in its design -- treatment assignment will exhibit some uneavenness with near certainty, but the average number of respondents should remain across all six treatments. ## Sixth pilot Following data collection using the participant pool drawn from Amazon Mechanical Turk, we will now proceed with the same instrument using a participant pool drawn from CrowdFlower. The purpose of this pilot is to test the instrument with a new sample before making another set of modifications.