[Solved] Describe four different research methodologies used in developmental psychopathology. Extradyadic Sex: Sexual activity that occurs outside of a committed relationship, often considered a breach of exclusivity. Erotic Plasticity: The degree to which an individual's sex drive and sexual interests can change based on various social, environmental, and situational factors. Cheating: The act of being dishonest, deceitful, or breaking rules to gain an unfair advantage. Jealous: Feeling or showing suspicion of someone's achievements or advantages, or fear of losing affection or position to a rival.