Instinctual variant theory holds that your instinctual drives can be divided into three forces. The Sexual force drives you to seek closeness, like you would experience in a strong romantic relationship or a close friendship. The Social force drives you to consider the wider community, where you and others stand, what everyone thinks/feels/needs of you and what you think/feel/need of them. The Self Preservation force drives you to maintain individual concerns - security, health, comfort, etc.. Each person will have a different mix of these three variants. Your results suggest the following mix:
Sexual |||||||||||| 38%
Social ||||||||||||||||||||| 62%
Self Preservation |||||||||||||||||| 58%
IMO it's hard to measure instincts apart from e-type because they manifest so differently. (For example, the Self-Pres instinct in 4s is thought to contribute to a need to live life "on the edge" to escape mediocrity and mundaneness, instead of the typical risk-aversion and safety/security-seeking that this test associates with the sp-instinct.)
I still think I'm sp/sx and the reason why I scored so low on sx instinct is because of my shyness; a lot of the questions about the sx instinct had more to do with acting on/externally pursuing intensity instead of internally focusing on it, and I think a craving for deep intimacy and intensity but having difficulty getting out of one's shell in order to obtain it is common for sp/sx types. I believe it's especially common for highly introverted 9w1s with strong sx instinct to be focused on intimacy and intensity but have trouble actually pursuing it outside of their imaginations.
“If you hate a person, you hate something in him that is part of yourself. What isn't part of ourselves doesn't disturb us.” - Hermann Hesse