Anthropic Bias explores how to reason when you suspect that your evidence is biased by observation selection effects--that is, evidence that has been filtered by the precondition that there be some suitably positioned observer to have the evidence. This conundrum--sometimes alluded to as the anthropic principle, self-locating belief, or indexical information--turns out to be a surprisingly perplexing and intellectually stimulating challenge, one abounding with important implications for many areas in science and philosophy.

There are the philosophical thought experiments and paradoxes: the Doomsday Argument; Sleeping Beauty; the Presumptuous Philosopher; Adam & Eve; the Absent-Minded Driver; the Shooting Room.

And there are the applications in contemporary science: cosmology (How many universes are there?, Why does the universe appear fine-tuned for life?); evolutionary theory (How improbable was the evolution of intelligent life on our planet?); the problem of time's arrow (Can it be given a thermodynamic explanation?); quantum physics (How can the many-worlds theory be tested?); game-theory problems with imperfect recall (How to model them?); even traffic analysis (Why is the 'next lane' faster?).

Anthropic Bias argues that the same principles are at work across all these domains. And it offers a synthesis: a mathematically explicit theory of observation selection effects that attempts to meet scientific needs while steering clear of philosophical paradox.