This chapter explores handedness consistency as a neuropsychological individual difference variable that predicts decision-making patterns. Consistent-handers (CH) and inconsistent-handers (ICH) differ in corpus callosum size and interhemispheric interaction, leading to predictable variations in cognitive processing. When tasks require integration of lateralized dual processes, ICH show superior performance and larger experimental effects due to increased interhemispheric communication. Conversely, when tasks demand hemispheric independence, CH demonstrate advantages. These differences manifest across various decision-making domains including risk perception, framing effects, loss aversion, and belief updating. The research reveals that ICH are more susceptible to belief updating, persuasion, and anchoring effects, while CH show greater loss aversion, discount rates, and hindsight bias under certain conditions. Practical applications include tailored public health messaging, enhanced eyewitness testimony protocols, and improved understanding of individual differences in decision-making. The findings suggest that handedness consistency serves as an accessible proxy for underlying neurological differences, offering both theoretical insights and practical applications for predicting and potentially modifying decision-making behaviors through targeted interventions.