Are Writers Narcissistic or Altruistic?

Mary Karr, the award-winning poet and New York Times best-selling memoirist, reportedly opined:

All writers are narcissistic [...] No one can sit in a room by themselves for 12 hours a day thinking about what they're thinking and not be a little more self-focused than the normal person. You're definitely on the far end of the [racist] bell curve. 

And per Poetry School, Sylvia Plath said: 

I think writers are the most narcissistic people. 

But Dictionary.com defines narcissism [ nahr-suh-siz-em ] as an: "inordinate fascination with oneself; excessive self-love; vanity."

And this is how the Mayo Clinic defines narcissistic personality disorder:

Narcissistic personality disorder [...] is a mental condition in which people have an inflated sense of their own importance, a deep need for excessive attention and admiration, troubled relationships, and a lack of empathy for others. 

Thus, I would disagree with Karr's and Plath's assessment that (most) writers are narcissistic. I don't think that (most) writers possess "excessive self-love" and have "a deep need for excessive attention". 

On the contrary, I would opine that (most) writers are altruist, because they "sit in a room by themselves for 12 hours a day", because they desperately want to share their art (with the world). 

"American Horror Story: Double Feature": Write Under the Influence

On American Horror Story: Double Feature (s10e04), Belle Noir is on a self-financed book tour for her self-published romance novel, Martha’s Cherry Tree, which is a "[...] racy retelling of the

George and Martha Washington story." 

In chapter 17, Martha discovers that George has been in one of the maid's bed, "little innocent" Penelope, but instead of confronting George, Martha seduces the maid by: "[...] kissing her hairy warmth between the young maid's legs."

(Maid [ \ ˈmād \ ] noun : an unmarried girl or woman especially when young : VIRGIN. [Merriam-Webster])

Although, Noir was informed, "You're a good writer," there were (only) four bookworms at the reading, and Noir (only) sold one book. Consequently, she took a pill that would super enhance the quality and speed of her writing; thus, Noir wrote a 400 plus page novel in one night, but the pill had horrible side-effects. 

If a writer doesn't want to end up like Noir or, say F. Scott Fitzgerald, we advise writers to, like Voltaire, write of the influence of coffee but, unlike Balzac, not too much. 

BIG BROTHER (2021): An Case of Joy [Versus Misery]

In the above GIF from Big Brother (2021), Derek F., Azah, Tiffany, and Hannah  are experiencing extreme joy; so much so, that their bodies, literally, couldn't bear the weight of the emotion. 

Derek F. braces himself on the designer sink. Azah and Tiffany drop to their knees. And Hannah looks quickly for a place to sit before plopping onto the bed. 

But interestingly, the body can react to joy and misery in similar ways. It's not uncommon to see people react to, say, the news of a deceased loved one by plopping, bracing and/or dropping to their knees. The main difference is that misery is often coupled with crying while joy and laughter are often couples.