A theory divided: Current representations of the anchoring theory of lightness contradict the original's core claims

- The anchoring theory of lightness is conceptually incoherent.
- Current claims contradict the original proposal without rejecting it.
- The theory is too vague and shifting to be falsifiable and thus lacks heuristic value.
- In light of this, the theory does not seem scientifically viable.

The anchoring theory of lightness perception (Gilchrist et al., Psychological Review 106 (1999) 795-834) has been described as one of the most successful approaches to lightness perception. Yet, not only does the original proposal contain serious gaps and inconsistencies, later expressions of the theory, which was never formally revised, seem to contradict the original claims while leaving the gaps unresolved. These problems call into question the theory's viability.