Economics and management theories predict that, since individuals are generally risk averse, incentive mechanisms should try to suppress any source of uncertainty in the relationship between effort and reward. However, animal research in psychology and neuroscience postulates that uncertainty about reward enhances behavioral invigoration of animals in various tasks. For example, it is well established that when circumstances are aversive and there is greater uncertainty about the possibility of obtaining food, animals increase their foraging activity, reflecting a stronger motivation to seek food. Some authors have pointed out that this psychological mechanism has been acquired by natural selection as an insurance against starvation. Expending effort in uncertain situations may be beneficial to better understand and predict the situation in the future. In this talk, I will present some studies that test whether these observations have implications for human behavior in the area of incentive design (and risk attitudes).