Human Vocabulary Use as Display

Abstract

The average human vocabulary consists of approximately 20,000 word families, yet only 6000-7000 word families are required to understand most communication. One possible explanation for this level of redundancy is that vocabulary size is selected as a fitness indicator and is used for display. Human vocabulary size correlates highly with measurable intelligence and when choosing potential mates individuals actively prefer other correlates of intelligence, such as education. Here we show that males used more low frequency words after an imaginary romantic encounter with a young female shown in a photograph relative to when they viewed photographs of older females. Females used fewer low frequency words when they imagined a romantic encounter with a young male shown in a photograph relative to when they viewed photographs of older males. These differences in male and female vocabulary displays may be related to sex differences in investment costs in offspring.