# altruism

/ˈæɫtɹuˌɪzəm/ (US) · /ˈɔːltɹuːˌɪzəm/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/altruism
Updated: 2026-05-18

## Definition

the quality of being selfless and caring for others without expecting anything in return. You use this to describe someone who helps others just because it is the right thing to do.

For teachers: the selfless concern for the well-being of others, typically involving a sacrifice of one's own interests. Often used in evolutionary biology to describe behaviors that benefit the group at a personal cost.

## Examples

- True altruism is rare in nature.
- The biologist studied altruism in wolves, noting how they often protect the pack's young even if it puts themselves at risk.
- Evolutionary theory struggles to explain altruism because natural selection favors traits that increase individual survival and reproductive success, yet many species exhibit behaviors that benefit the collective at a personal expense.

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