Farreley et al's (2013) study asks whether competitors who choose red have higher testosterone levels. The authors considered research by Hill and Barton (2005) who concluded that Olympic athletes had a higher probability of success when assigned red uniforms. Red uniforms were associated with better performance in soccer and online games. Barton and Hill's (2005) question of whether testosterone levels increased following wearing red was mentioned, but the authors note that no support was found. The authors suggest that red may signal competitive quality through higher testosterone levels and refer to Setchell and Dixson (2001), who found that higher testosterone levels may be evident in natural red coloring, including skin pigmentation, particularly in non-human primates. These points lead researchers to suggest that those with higher testosterone levels would more likely choose red as a sign of competitiveness. The reasoning leads to two hypotheses; one suggesting that those with higher testosterone levels would choose red, a second suggested that associations with dominance, threat and aggression would be stronger in individuals who chose red. Both are one-sided. The assumptions were clear, but the second assumption was not included in the rationale, suggesting that, while valid, it may have been an afterthought. The rationale was strong, even though it included active breeding and biological presentation. It might have been beneficial to discuss just one type. The experimental manipulation involved 73 males. The table below shows the theoretical and operational variables. At the theoretical level, the hypothesis consisted of the choice of color as the dependent variable and the testosterone level as the independent variable. At the operational level, the dependent variable was the choice of username symbol color between red and blue, and salivary testosterone level was the independent variable. The second hypothesis consisted of a description