The dopamine system tends to be curious, creative, spontaneous, energetic, restless, enthusiastic, impulsive, and mentally flexible. Explorers and risk takers. They are very good at idea generation. They can’t tolerate people who are boring. These people are drawn to others like themselves. 

The serotonin system tends to be more sociable and eager to belong. They’re quite traditional in their values and less inclined toward exploration. These are the builders and the guardians. They are calm, cautious, controlled, like to make plans, persistent, concrete thinkers, detail-oriented, structured, fact-oriented, loyal. They prefer loyal people over interesting or exciting people. They’re drawn to people like themselves. 

The testosterone system tends to be tough-minded, direct, decisive, skeptical, competitive, emotionally contained, inventive, experimental,exacting, analytical and assertive. They tend to be good at rule-based systems (engineering, computers, mechanics, math, and music). Rank-oriented directors. They are drawn to people opposite of themselves. 

The estrogen system tends to be intuitive, introspective, holistic, imaginative, trusting, empathetic, and contextual long-term thinkers. They are sensitive to people’s feelings, and typically have good verbal and social skills. These people are negotiators. They’re big-picture thinkers, tolerate ambiguity well, have mental; flexibility and strong executive social skills. They’re highly emotionally intelligent. These people are drawn to people opposite of them.