Envy is often associated with the color green, as in "green with envy", and yellow. Yellow is the color of ambivalence and contradiction; a color associated with optimism and amusement; but also with betrayal, duplicity, and jealousy. The phrase "green-eyed monster" refers to an individual whose current actions appear motivated by jealousy not envy. This is based on a line from Shakespeare's "Othello". Shakespeare mentions it also in "The Merchant of Venice" when Portia states: "How all the other passions fleet to air, as doubtful thoughts and rash embraced despair and shuddering fear and green-eyed jealousy!" The character Envy from Fullmetal
Jealousy protect their partner. Experts often believe that sexual jealousy is in fact a biological imperative. It may be part of a mechanism by which humans and other animals ensure access to the best reproductive partners. It seems that male jealousy in heterosexual relationships may be influenced by their female partner's phase in her menstrual cycle. In the period around and shortly before ovulation, males are found to display more mate-retention tactics, which are linked to jealousy. Furthermore, a male is more likely to employ mate-retention tactics if their partner shows more interest in other males, which is more likely to