Slepian & Ames - Materials 1. Images of cards used to play mixed-motive game –Each player received 6 cards (2 High, 2 Low, 1 Don’t Trust, 1 Trust) –Back of cards are illustrated 2. Back half of score sheet –Place for participant’s name and participant # –Place to record behavior and judgment for both target and counterpart per each round Including information about the target (their name and number) and how familiar the participant is with their counterpart – filling in the bubbles on the left, ranging from “H” (highly) to “L” (lowly) familiar –Place for participants to calculate their own payoff although researchers should re-calculate this for any analyses involving payoffs –Place for participants to calculate their own descriptive statistics at the end of the game although researchers should re-calculate this for analyses using averaged scores –Place for participant to predict [in brackets] – after receiving instructions about the game but before playing with any counterparts – how much they will get trusted, how often they will tell the truth, how much they will trust counterparts, how often counterparts will be truthful, how accurately they will judge counterparts, and how accurately counterparts will judge them 3. Front half of score sheet –Includes instructions provided to the players (consult to understand how cards are used) –Contains locations to place cards for the game 4. Payoff matrix (in color) for presentation purposes – used when walking players through the game 5. Payoff matrix (in black & white) – printed for players –Thick grid added to guide players how to find their payoffs –First find major quadrant (thick border), and then find minor quadrant within (thin border)

The High-Low game

1 Did they trust me? Did I lie? Did I trust them? Did they lie? Trust Don’t trust Truth Lie Trust Don’t trust Truth How frequently were you trusted? How frequently did you lie? How frequently did you trust? How frequently did others lie? ________% How accurately did people read you? _________% How accurately did you read other people? ________% Lie Number of cases where they trusted and you told the truth or they didn’t trust and you lied (note points earned in each round below) Payoff Sum Your # Counterpart name [ # ] [ ] Number of cases where you trusted and they told the truth or you didn’t trust and they lied SCORING LOG Your name [ ] H L H L H L H L H L H L H L H L H L H L

Step 1 Private Draw Step 2 Public Play Step 3 Trust Choice Fan out your High-Low cards facedown and randomly draw one; this is your Private Draw Privately look at that card and remember whether it says “High” or “Low”; don’t show it to your counterpart Place the card face down above, without showing it to your counterpart Look at your remaining High-Low cards face up so that only you can see them Choose one as your Public Play— what you will claim your Private Draw card is Playing the same card for your Public Play as your Private Draw card counts as telling the truth; playing a different card counts as lying Regardless of whether your cards actually match, you should try to convince your counterpart that they do match—that is, to trust you that you’re telling the truth Place your card face down Place your card face up Choose whether you trust your counterpart’s Public Play matches their Private Draw Choose your Trust card if you believe their cards match (they’re telling the truth); choose Don’t Trust if you believe they don’t match (they’re lying) Place your Trust Choice card face down above initially Once both of you have played your Trust Choice cards face down, flip them both face up Record your outcome on your log (see reverse side of sheet) Place your card face down FIRST NAME LAST NAME Please print clearly GAME PLAY SHEET

You trust OPYou don’t trust OP OP tells truth (+10 for you) OP lies (-20 for you) OP tells truth (0 for you) OP lies (0 for you) OP trusts You You tell truth (+10 for you) You lie (+20 for you) OP doesn’t trust You You tell truth (0 for you) You lie (0 for you) Your score in blue[OP’s score in brackets] You will make two choices: 1 Trust OP vs. Distrust OP 2 Lie to OP vs. Tell the Truth OP* will make two choices: 1 Trust You vs. Distrust You 2 Lie to You vs. Tell the Truth Your payoffs, and OP’s payoffs, depend on all four of these choices +20 [+20] +30 [-10] -10 [+30] 0 [0] +10 [+10] -20 [+20] +20 [-20] 0 [0] +10 [+10] * OP = Other Person

You trust OPYou don’t trust OP OP tells truth (+10 for you) OP lies (-20 for you) OP tells truth (0 for you) OP lies (0 for you) OP trusts You You tell truth (+10 for you) You lie (+20 for you) OP doesn’t trust You You tell truth (0 for you) You lie (0 for you) Your score in bold[OP’s score in brackets] You will make two choices: 1 Trust OP vs. Distrust OP 2 Lie to OP vs. Tell the Truth OP* will make two choices: 1 Trust You vs. Distrust You 2 Lie to You vs. Tell the Truth Your payoffs, and OP’s payoffs, depend on all four of these choices +20 [+20] +30 [-10] -10 [+30] 0 [0] +10 [+10] -20 [+20] +20 [-20] 0 [0] +10 [+10] * OP = Other Person