Macroscopic Complementary Relation Between Subjective Observations and Objective Measurements of Colors

In the Generalized Quantum Theory (GQT), a theory designed to describe psychophysical phenomena, the subjective and objective aspects of reality are considered to be complementary. The research presented here focused on investigating such a macroscopic complementarity between subjective and objective reality descriptions within the context of color assessment. In particular, the non-commutability conjecture of the GQT posits that two observables derived from the subjective and objective subsystems do not simultaneously provide specific eigenvalues. Rather, the act of measurement within one subsystem, e. g. the performance of objective measurements on a stimulus, modifies the state of the entire system, including the eigenvalues of the other subsystem, e. g. the subjective experience of this stimulus. This conjecture was tested empirically in four studies and in three overall analyses of the complete data set combining all four studies. The experimental manipulation involved a measurement variation of one aspect of the supposed complementary pair, namely the storage (non-erasure condition) or deletion (erasure condition) of objective color parameters (hue and lightness). It was anticipated that the erasure manipulation would influence the other part of the pair, namely the subjective evaluations of color with respect to brightness and likability. The primary hypothesis, which tested erasure-dependent effects on variations in subjective brightness scores was confirmed in Studies 1 and 2 but could not be replicated in Studies 3 and 4. The initial findings obtained with this dependent variable can thus be considered false positives and the primary hypothesis could not be confirmed. However, the second hypothesis, which tested erasure-effects on subjective likability mean scores revealed the following results: The exploratory findings from Studies 1 and 2, as well as the confirmatory findings from Studies 3 and the preregistered Study 4, indicated an erasure effect on subjective likability, whereby higher likability scores were observed in the non-erasure condition compared to the erasure condition in each study. Since the experimental design was intentionally contaminated by a “color bias” alternative explanation to stabilize the effect documentation, a clear causal erasure interpretation cannot be provided at the single study level. To overcome this contamination an overall analysis strategy was pre-planned and performed on the combined data set. Several overall analyses ruled out the “color bias” alternative explanation and another confound. In conclusion, the overall results provided evidence for an erasure effect on subjective likability supporting the model of GQT. This can be interpreted as macroscopic complementary relations between objective and subjective reality descriptions as proposed by the GQT. The implications of these findings for our understanding of the nature of reality and for the validity of the GQT are discussed.