Biases in thinking
Self-serving bias
People credit their successes to themselves and blame failures on circumstances or other people.
When a launch goes well, the team's strategy worked; when it flops, the market changed. Users do it too: they succeeded, or the product failed them.
In retrospectives, ask what you'd say if a competitor had made the same decision. In products, assume a user's mistake is a design problem until shown otherwise.
In practice
A team credits a rise in sign-ups to its redesign without checking that a holiday sale ran the same week.
Common mistake
Blaming 'user error' for problems that keep happening. If many people make the same mistake, the design invites it.
Where it comes from
Reviewed by Dale Miller and Michael Ross in 1975, drawing on research into how people explain success and failure.