📈 The IQ Zoo 📉

1. How does the ranking system work?

We use an Elo rating system, it's the same method chess tournaments and online games use to rank players. Every animal started with a score of 1200. When you pick which one you think is smarter, the scores shift depending on the ratio between the starting scores of the two animals. See below for the equation.

2. Do the scores correlate in some way to IQ scores?

Absolutely not.

3. What do the scores actually mean?

The scores mean one thing and one thing only: they show how intelligent people perceive the animal to be. A higher scoring animal is not objectively smarter (what would that even mean?) it simply means, on average people subjectively perceive this animal to be smarter than one with a lower score.

4. Isn't this all just subjective?

Yes, see above.

5. Why do you have generic categories like "fish" or "camel" in some cases and specific species in other cases?

For animals where people aren't likely to know the specifics, we keep it simple—"fish" works just fine. But for animals like dogs, apes and whales, where species are more likely to be known, and perceived intelligence is likely to differ, we get a bit more specific. See question 6.

6. Is this scientific at all?

No.

7. Why didn't you add animal [my favourite animal here]?

It's nothing against your beloved [your favourite animal here], I probably just forgot. There are lots of animals out there, I'm sure I missed some important ones. Ask me to add it if you want.

8. What is the Elo score change equation?

expected_score = 1 / (1 + 10^((opponent_rating - player_rating) / 400))
Winner: actual_score = 1
Loser: actual_score = 0
change = K_FACTOR * (actual_score - expected_score)
Note: We use a K_FACTOR=32

An example, with Ant (1200) vs Dolphin (1300)
expected_score = 1 / (1 + 10^((1200 - 1300) / 400)) = 0.64
Therefore we expect the Dolphin to win 64% of matches.

If the Dolphin wins the score change is...
Dolphin = K_FACTOR * (actual_score - expected_score) = +12
Ant = K_FACTOR * (actual_score - expected_score) = -12

If the Ant wins the score change is...
Dolphin = K_FACTOR * (actual_score - expected_score) = -20
Ant = K_FACTOR * (actual_score - expected_score) = +20

Note: We use a K_FACTOR=32

9. Can I contact you with issues or questions? I want to add an animal you forgot.

Yes, the project is here