There is no specific gene identified for jealousy in humans, and while some genes may correlate with behaviors associated with jealousy, none have been conclusively proven to exist. Brain activity related to jealousy can be observed through MRI scans, indicating that certain brain areas are involved in this emotion. The brain's adaptability suggests that experiences of jealousy can influence future reactions and emotional responses. Personality traits, including jealousy, are likely the result of a complex interplay of multiple genes and environmental factors. Overall, jealousy is shaped by both genetic predispositions and individual experiences.