初级Beginner在线实验室Online lab可打印Printable

猴子共和国：香蕉怎么分？

Monkey Republic: How Do We Share the Bananas?

两个动作、四格收益表。先争取自己的香蕉，再比较双方总数，发现比赛目标会影响选择。

Two actions and a four-cell payoff table. Compare your own bananas with the pair total and see how a scoring goal changes choices.

用香蕉糖或剪纸玩：两人各先拿5枚，银行留30枚，分数从0记。每轮同时选择分享或抢，再按表向银行领还；实物每局最多5轮。自己多拿一点和双方合计多拿一点，答案会一样吗？

Play with banana candy or paper cutouts: start five per player and 30 in the bank, with scores at zero. Choose Share or Grab together, then take or return the table’s payoffs. Physical matches last up to five rounds. Does earning more for yourself mean earning more together?

开始之前Before you start

独立查收益表，算出自己、对方和合计收益；用一个反例区分个人得分与双方总数。

Read the payoff table independently, total both players and the pair, and give a counterexample separating personal gain from pair gain.

会加减小整数；把 −1 解释为“还给银行1枚”。起始5枚不计分，重开局时恢复库存。不需要代码或账号。

Add/subtract small integers. Explain -1 as returning one to the bank. The starting five are not score; restore stocks when restarting. No code or account is required.

一步一步试试看Try it step by step

先猜（5分钟）：先亮两人的选择，再查四格表：SS=3/3，SG=−1/5，GS=5/−1，GG=0/0。每组先走一次例题，确认左／右玩家没有看反。Predict (5 min): reveal both choices, then use SS=3/3, SG=−1/5, GS=5/−1, GG=0/0. Work one example and check which number belongs to each player.
动手（10分钟）：目标一是自己的总数。每轮两人先选牌、盖住、一起翻开，记录三轮。课堂实验也要等两边都锁定后才揭晓。Play (10 min): aim first for your own total. Choose cards face down, reveal together and record three rounds. The lab also waits for both choices to lock before revealing.
观察（10分钟）：目标二改为双方合计，其余收益不改。再玩三轮，比较每轮个人数和合计数；这是课堂计分任务，不是原游戏新增的团队胜利模式。Observe (10 min): change the classroom objective to pair total, keeping payoffs fixed. Play again and compare individual versus combined gains; this is a classroom scoring task.
挑战（10分钟）：找出“我这一轮拿得更多，但两人合计更少”的例子，再和原信任游戏的 3/5/0/1 表对照，不能混用答案。Challenge (10 min): find a move that increases your current gain but reduces the pair total. Compare with the original trust game’s 3/5/0/1 table without mixing answer keys.

一起算一个例子Work through one example

三轮 SS、SG、GG：左猴 3−1+0=2，右猴 3+5+0=8，合计 10。都是分享时每轮合计 6，一方抢时合计 4。

For SS, SG, GG: left earns 3−1+0=2, right 3+5+0=8, pair total 10. Sharing together gives six per round; one grab gives four.

先想一想，再看答案Think first, then check

对方分享时，我抢能多拿多少？这时双方合计反而少多少？能据此证明所有重复游戏都应该一直抢吗？

If the other shares, how much more do I get by grabbing? How much does the pair lose? Does that prove always grabbing is best in every repeated game?

查看参考答案Show the expected answer

本轮个人多 2（5−3），合计少 2（6−4）；不能推广到所有重复对手。学习单：对方 S 时个人 G 的 5>3；对方 G 时个人 G 的 0>−1。SG、GS、SS 三轮左右各 7，合计 14。团队目标下 SS 每轮合计 6 最大；个人当前回合的比较则偏向 G。自编三轮答案按同一张表逐轮相加。

The individual gains two (5−3) while the pair loses two (6−4). This does not establish a universal repeated-game strategy. Worksheet: against S, G gives 5>3; against G, G gives 0>−1. SG,GS,SS totals seven each and 14 together. SS maximizes the current pair total at six; G maximizes the current personal payoff. Check children’s puzzles with this same table.

这个实验说明了什么What this experiment shows

只说明指定收益与目标下的结果。香蕉分数不是同学品格分数；一次遭遇的比较不能替代重复博弈的分析。此处不用原信任游戏的 0/5、1/1 计分。

Results depend on the stated payoffs and objective. Banana scores do not grade children’s character; one encounter does not solve every repeated game. Do not substitute the original trust game’s 0/5 and 1/1 outcomes.