Is social anxiety a part of human gene pool and caused by natural selection?

Question

I'm reading a book called 'Why Buddhism Is True' and I'm not sure I understand author's point regarding social anxiety and natural selection:

Our ancestral environment didn’t feature cocktail parties, slumber parties, or PowerPoint. Our hunter-gatherer ancestors didn’t have to navigate roomfuls of people they’d never met or send their children off to sleep in homes they’d never seen, or give presentations to an audience consisting largely of people they didn’t know very well, if at all.

Just to be clear (and at the risk of repeating myself), I’m not saying that social anxiety isn’t in any sense a product of natural selection. The ancestral environment—the environment of our evolution — featured lots of social interaction, and this interaction had great consequence for our genes. If you had low social status and few friends, that cut your chances of spreading your genes, so impressing people mattered, even if PowerPoint wasn’t the thing you impressed them with. Similarly, if your offspring didn’t thrive socially, that boded ill for their reproductive prospects, and hence for your genes. So genes inclining us toward anxiety about our social prospectsand our progeny’s social prospects seem to have become part of the human gene pool.

So, from what I've understood, author claiming that the fact that we have social anxiety around people which we probably will never meet again is caused by the fact that in the past every social interaction mattered. Is it true from science perspective? I mean, the people who weren't social in the past would just die without passing their genes, how the social anxiety can become in the human gene pool in this case?

I always thought that social anxiety/confience it's just byproduct of all the events which happens with a child(if a child's social behaviour is positively reinforced then there would have less fear in regards to socialazing, public speaking, leadership etc).

PS: English is not my mother tongue, so I might formulate the question not clearly enough, so, it would be ideal if you can get additional context by clicking on the link and reading the chapter which the passage belongs to(6 pages). Just to be sure the answers aren't based on my interpretation of the author thoughts, but rather on the actual text of the book.

Answer 1

Short answer - Probably not.

When we talk about traits in evolution, we generally talk about things that are absolute (for example, you either have an attached earlobe or you don't). However, a psychological phenomenon as complex as social anxiety is definitely not controlled by a singular trait. Instead, a number of traits, if found, lead to the phenomenon (things such as physical appearance, susceptibility to sadness et cetera).

This is not to say that the phenomenon doesn't have its roots in genetics, some part of it might be controlled by genetics as well. But logically it's much more plausible that a psychological phenomenon such as social anxiety is dependant on environmental factors much more than genetic factors.

We hear countless stories of people who used to be socially anxious but bettered themselves by forcing themselves out of their comfort zones. This would not have been possible if the trait was genetically controlled.

One other thing to be wary of (as mentioned in a comment on your question) is the fact that many people use false claims of 'darwinism' in order to make their pseudoscience seem legitimate. There is no proof currently that proves it so, and probably never will be.