1.
group action; collective behavior; acting as a group
Behavior or actions performed together as a group rather than individually. An important concept in Japanese schools and workplaces, where coordinated group activity is emphasized.
集団行動が苦手だ。
I'm not good at group activities.
学校では集団行動の大切さを学ぶ。
At school, you learn the importance of group behavior.
災害時には落ち着いて集団行動を取ることが求められる。
During a disaster, people are expected to remain calm and act as a group.
Compound of 集団 (group/collective) + 行動 (action/behavior). Common collocations: 集団行動を取る (to act collectively), 集団行動が苦手 (to be bad at group activities). In Japanese education, 集団行動 is actively taught and practiced, including synchronized marching and group exercises during sports festivals. Contrasts with 個人行動 (individual action) and 単独行動 (acting alone).