Given the frequency of Enneagram 7s and 8s who mistype as each other (usually the former mistyping as the latter) and the amount of misinformation pertaining to both types, I thought I would offer my take on the similarities/differences between 7s and 8s. naturally, feel free to share any thoughts or points of dissent.
Disclaimer: In the tradition of Enneagram theorists such as Naranjo and Maitri (whose works I have consulted but not, to my knowledge, directly cited) I have chosen to focus more on the negative aspects of both types to avoid the Forer Effect and attribution bias. while the similarities section is more broad and trait based, the differences section will attempt a more causal analysis and explain the neuroses of both types. Keep in mind, I am describing natural tendencies rooting in the fixations that are both types. Outward acting upon or manifestation of said tendencies need not be present in all 7s or 8s, but, regardless of level of health, the inclinations will be there.
Id driven, shallow experience of emotion (except anger), flood themselves with stimulation in order feel alive, needs of self>needs of others, significant disregard for authority (which they typically don’t believe in in the first place) and difficulty fitting into hierarchical structures unless they are taking charge, able to force peoples' hands with the sheer impact of their personalities (and both prefer to as a first instinct, even though many 7s and 8s are highly intelligent), belief that they are invincible, enjoy pushing people’s buttons, may be prone to criminal behavior, provocative sense of humor with hardy laughter, lack a sense of societal obligation, staunchly resist externally imposed responsibilities, delayed emotional response to negative situations, seek power and control, internal sense of emptiness, strong sense of adventure, egocentric, prefer life in excess, sexually lusty and indulgent, assertive, confident, do not question what they want, make aggressive demands on the world, general "who cares?" attitude to most of life