Women's participation in small-scale aquaculture is growing, but women producersremain in a disadvantaged position compared to men. Reducing gender gaps is at thecore of many development programs, but little is known regarding the source ofthese differences. This paper investigates the main drivers of gender gaps in seaweedsmall-scale aquaculture by focusing on the analysis of differences between male andwomen, and across a series of psychological traits. We use data from a sample of152 seaweed producers from central-southern Chile and perform a matching proce-dure to generate a balanced sample of male and female producers in the dimensionsdetermining their performance in the sector. Our results show that female producersmay exhibit more positive psychological traits such as patience and interpersonaltrust. However, women's choices in seaweed farming may be incongruent with thesecharacteristics, as expecting more immediate returns than males, and may not be ableto exploit the advantages of collaboration in selling in the sector. This supports thenotion that opportunity costs (e.g., other activities in the marine area) and outsideoptions (e.g., fishing versus trade) may be one of the major drivers of gender gapsand suggests that there are barriers keeping women from exploiting their potentiallyadvantageous individual characteristics. Results provide important insights for thedesign of support instruments aimed at reducing these barriers faced by women inthe sector.