Q1. What is the passage mainly about?

1. AHow to win a tug-of-war
2. BHow to make a group chat
3. CWhy people put in less effort in groups
4. DWhy blindfolds are useful

集団になると一人ひとりが手を抜く「社会的手抜き」がテーマなので C。

Q2. What helps people answer in a group chat?

1. ASending the question to more people
2. BAsking one person by name
3. CWaiting for a long time
4. DUsing a blindfold

Asking one person by name helps. とあるので B。

Q3. In this passage, "blindfolds" are ...

1. Acloths that cover the eyes
2. Blong ropes
3. Cheavy shoes
4. Dgroup leaders

目隠しをして周りが見えない状態にした実験なので、blindfold は「目隠し（の布）」。A。

Q1. What did Ringelmann find?

1. AEach person pulled with less force as more people joined.
2. BEach person pulled harder in a larger group.
3. CRopes break when many people pull.
4. DGroups always win against individuals.

as more people pulled a rope, each person pulled with less force とあるので A。

Q2. Why was the 1974 experiment important?

1. AIt showed that timing problems were the only cause.
2. BIt proved that blindfolds make people stronger.
3. CIt found that people pull harder alone in the dark.
4. DIt showed that lower motivation was part of the cause.

ひとりで引いているのに他の人もいると思うだけで力が落ちたので、lower motivation was part of the cause とわかった。D。

Q3. According to the 1993 analysis, when does social loafing become smaller?

1. AWhen groups become larger
2. BWhen nobody knows who did what
3. CWhen each person's contribution can be seen
4. DWhen the task is boring

it becomes smaller when each person's contribution can be seen or when the task feels meaningful とあるので C。

Q1. What did the 1974 study help to show?

1. AThat coordination problems were the only cause of lower force
2. BThat blindfolds improve teamwork
3. CThat larger groups always pull harder
4. DThat a genuine loss of motivation contributes to social loafing

ひとりで引いているのに他者がいると信じただけで力が落ちたので、indicating a genuine loss of motivation。D。

Q2. Which of the following does NOT reduce social loafing, according to the 1993 meta-analysis?

1. AIdentifiable individual contributions
2. BA meaningful task
3. CValued group members
4. DA larger number of group members

貢献が見える・意味のある作業・大切なメンバー・努力が欠かせない、の4つが挙げられている。人数を増やすことは逆に手抜きを生むので D。

Q3. What does the 2002 email study suggest for group chats?

1. ASending a question to many people guarantees quick answers.
2. BAddressing a request to a specific person is likely to get a better response.
3. CEmails are always ignored.
4. DOnline communication has no diffusion of responsibility.

1人宛てのメールのほうが役に立つ返信を多く得たので、特定の人に宛てて頼むほうが良いと推論できる。B。