The article explores the tendency to avoid cognitive demand in decision-making, a principle often referred to as the "law of least mental effort." The authors conducted six behavioral experiments to evaluate this assumption, which has primarily been supported by evidence of effort minimization in physical tasks. The experiments involved participants choosing between actions with different levels of cognitive demand, such as task switching and problem-solving. The results consistently showed a bias towards selecting the less demanding option, regardless of strategic error avoidance, time minimization, or goal achievement maximization. This bias was also observed even when participants were unaware of the demand manipulation and was sensitive to task incentives and individual differences in executive control. The findings, supported by neuroscientific evidence, suggest that anticipated cognitive demand plays a significant role in behavioral decision-making.The article explores the tendency to avoid cognitive demand in decision-making, a principle often referred to as the "law of least mental effort." The authors conducted six behavioral experiments to evaluate this assumption, which has primarily been supported by evidence of effort minimization in physical tasks. The experiments involved participants choosing between actions with different levels of cognitive demand, such as task switching and problem-solving. The results consistently showed a bias towards selecting the less demanding option, regardless of strategic error avoidance, time minimization, or goal achievement maximization. This bias was also observed even when participants were unaware of the demand manipulation and was sensitive to task incentives and individual differences in executive control. The findings, supported by neuroscientific evidence, suggest that anticipated cognitive demand plays a significant role in behavioral decision-making.