Abstract
Many languages without separate terms for “green” and “blue” are or were spoken by people in locations receiving above-average exposure to ultraviolet-B (UV-B) radiation. Lindsey and Brown (2002) suggest this increased exposure to UV-B radiation could explain the lack of a separate term for “blue” in these languages due to premature lens brunescence. To test this hypothesis, we examined color-naming patterns in 20 native English speakers with a wide range of ocular media (lens and cornea) optical densities (OD). Ten younger (18–35 y.o.) and ten older (65–85 y.o.) trichromats were tested. The ocular media OD of one eye of each observer was measured using a technique described by Van Norren and Vos (1974). Two sets of stimuli were tested. The first set consisted of 40 simulated Munsell chips presented on a CRT as 2 disks on a gray (illuminant C) background. The second set was a modification of the first such that older subjects viewed stimuli that simulated chips filtered through the ocular media of an average younger observer, while younger subjects viewed stimuli that simulated chips filtered through the ocular media of an average older observer. Each stimulus was presented 4 times and observers chose which of 11 basic color terms best described the stimulus. Replicating Lindsey and Brown (2002), we found younger subjects used “bluerd significantly less often in the simulated aging condition. However, for the first set of stimuli, older subjects used” bluerd just as often as younger subjects did. In fact, color naming in the younger and older groups was virtually identical for the first set of stimuli. Thus, we conclude that lens brunescence is not a mechanism that could explain the lack of a color term for “blue” in high UV-B areas. The correlation between high UV-B exposure and lack of a color term for “blue” may be better explained by other co-variants of tropical latitude, such as a low-level of technological complexity and paucity of color terms in general.
NIH AG04058