Q1. What is the passage mainly about?

1. AHow to make a nose spray
2. BWhether oxytocin really makes people trust others
3. CWhy news stories are always wrong
4. DHow hormones help babies grow

オキシトシンで信頼が増すという研究と、その再現の問題が中心なので B。

Q2. What happened when other scientists tried the same kind of test?

1. AThey got exactly the same result.
2. BThey found oxytocin was dangerous.
3. CThey often could not get the same result.
4. DThey stopped studying hormones.

They often could not get the same result. とあるので C。

Q3. In this passage, "trusted" means people ...

1. Abelieved that others were honest and reliable
2. Bwere afraid of others
3. Cforgot about others
4. Dtalked loudly to others

trust は「信頼する」。相手が正直で頼れると信じることなので A。

Q1. In the 2005 study, who knew whether a participant received oxytocin or a placebo?

1. AOnly the participants
2. BOnly the researchers
3. CBoth the participants and the researchers
4. DNeither the participants nor the researchers

neither they nor the researchers knew which one they received とあるので D。これを二重盲検法という。

Q2. Why might positive results in oxytocin studies have appeared by chance?

1. ABecause many studies used small samples
2. BBecause the spray was too strong
3. CBecause the games were too easy
4. DBecause only women took part

many oxytocin studies used small samples, so positive results might have appeared by chance とあるので A。

Q3. What does the Dutch study suggest about oxytocin?

1. AIt makes people kind to everyone.
2. BIt has no effect on behavior.
3. CIt may make people favor their own group.
4. DIt helps people win money games.

自分のグループとの協力が増え、ライバルには防衛的になる可能性があるので、仲間びいきを強めると推論できる。正解は C。

Q1. In the 2005 study, what did the men who received oxytocin do?

1. AThey refused to play the trust game.
2. BThey entrusted more money to an anonymous partner.
3. CThey kept all the money for themselves.
4. DThey chose to play only with their own group.

Those given oxytocin entrusted more money to an anonymous partner. とあるので B。D の「自分のグループ」はオランダの研究の話。

Q2. What does "statistically underpowered" imply about many studies?

1. AThey were too expensive.
2. BThey used too much oxytocin.
3. CThey lasted too long.
4. DTheir positive findings may be false positives.

which would mean that many of the published positive findings are false positives と説明されているので D。サンプルが小さく本当の効果を見つける力が弱いこと。

Q3. What is the main point of the passage?

1. AAn exciting early result about oxytocin and trust has not held up well in later research.
2. BOxytocin has no role in the body.
3. CProducts containing oxytocin improve relationships.
4. DNature never publishes mistakes.

2005年の研究で広まった評判が、The basic trust result has fared badly. 以降で、再現されない・追試で効果なし・検出力不足と次々に否定されているので A。体内での役割を否定してはいない。