Choice between the probability (100%, 75%, 50%, 25%, 10%, and 0%) and value of a reward was studied in adult humans. Behavioral experiments showed that humans placed in a situation of choosing between larger but risky rewards and smaller but always delivered rewards make decisions in accordance with situational factors and individual characteristics such as the inclination to risk and caution. In the situation of choosing between behavioral strategies, humans were divided into “risk-inclined” and “riskaverse,” or cautious. Individual-typological differences between people were greatest at the 25% probability of receiving the reward. Probabilistic prediction was more effective in “risk-inclined” subjects than “risk-averse” people. On psychological tests, “impulsive” people were more inclined to risk than caution. Synchronicity was seen in the EEG α and β rhythms in “risk-averse” groups of people in conditions of a 25% probability of receiving the more valuable reward.