How Smart Are Animals

2. something does not behave the same each time
5. Small animals often used in labs for testing; mentioned as examples along with pigeons.
9. To change gradually over time; a word defined in the text.
10. A careful test described that keeps both subjects and scientists "in the dark."
14. an experiment in which none of the people involved know the answers
15. type of animals that are most difficult to perform tests on
16. The horse involved in the famous intelligence story.

1. The human who investigated Clever Hans and used controlled tests.
3. What scientists compare across species; also a measure used in schools.
4. A primate group often considered very intelligent.
6. The ability to learn
7. A hint or signal people may give unintentionally.
8. Insect that was listed among animals questioned for thought.
11. An unusual or remarkable event
12. What some animals use to solve problems or catch food; also a sign of intelligence.
13. The name of the Newfoundland dog who rescued Andrea.