Stereotypes

I'm Canadian.  Canada is mad about hockey. Therefore I'm mad about hockey.

The fallacy is obvious, especially to anyone who knows me.

In family history we often try to fill in gaps in our family stories by looking at what was typical in the larger community.

Robert went to the Yukon in the early 1900s. He must have been a miner exploiting the spoils of the Gold Rush. Right?

No.

Robert Service was a bank clerk, newspaperman and poet.

It helps avoid such errors if you think in terms of the Venn diagram and probabilities.

Don't get fooled by stereotypes.