A hasty generalization draws a conclusion from insufficient evidence. You meet two rude people from a city and conclude everyone there is rude. You try one bad restaurant and decide all restaurants in the chain are bad. The sample is too small. The conclusion is too broad. The generalization is hasty.

The fallacy is common in everyday reasoning. Stereotypes are hasty generalizations. Prejudice is a hasty generalization. A single bad experience leads to a broad conclusion. The evidence does not support the conclusion. The sample is not representative. The conclusion is not justified.

Hasty generalization examples

• My grandfather smoked and lived to 90, so smoking is not harmful.
• I got sick after eating there, so the restaurant is unsanitary.
• Two people from that country were rude, so everyone there is rude.
• This product broke, so the brand is unreliable.
• The first three coin flips were heads, so the coin always lands heads.

Hasty generalization is a fallacy of insufficient evidence. The remedy is to gather more data. A larger sample is more representative. A controlled study is better than anecdote. The fallacy is common because anecdotes are vivid. A single story feels like evidence. It is not. It is one data point. One data point is not a pattern. The human mind is pattern-seeking. It sees patterns in noise. Hasty generalization is a natural error. It takes training to avoid. The next time you draw a broad conclusion from a small sample, ask: how many cases have I observed? Is the sample representative? The answer is often no. The generalization is hasty. It should be revised.