In line with their name as "The Achiever," Enneagram Threes are intensely focused on their own success. While being ambitious and hardworking can be good things, per Bustle, people with an Enneagram type Three are often too focused on appearing successful and accomplished in order to impress others, rather than simply focusing on fulfilling themselves and their goals. According to The Enneagram Institute, Threes "can also be overly concerned with their image and what others think of them." This is why they benefit greatly from being partnered with someone who is a cheerleader for them, and shows unconditional love and support — an Enneagram Three is most compatible with an Enneagram Nine.

Enneagram Nines, also known as "The Peacemakers," "are motivated by a need to be settled and in harmony with the world and, as a result, being accommodating and accepting will be important to them," as noted by Integrative9. For someone like an Enneagram Three, who tends to put intense pressure on themselves to impress others and prove themselves as successful, a partner who acts as a cheerleader for them and accepts them wholly for who they are is key. This is why Enneagram Nines make wonderfully compatible partners with Enneagram Threes; per Mind Body Green, "The effacing Nines can support the Threes' ambitions and, most importantly, innately accept them for who they are, not what they can do. This stability allows Threes to connect to their emotions. Likewise, Threes help the happy-go-lucky Nine move toward the spotlight and find respect and value in their own personhood."