If the sufferer had *not* been subjected to teasing and criticizing or the verbal and physical abuse, would they still suffer from social anxiety and low self-esteem?

I don’t think so. They learned the behavior and therefore were trained to behave that way. All of the various and repeated attacks weakened their self-esteem and damaged their self-image. They see themselves as damaged. When it is beaten in to you day after day, you begin to believe it.

I hope this is making some kind of sense.
Characteristics of Bullying Victims

* Kids who typify victims of bullying appear to be anxious, self-doubting, and insecure.
* Bullying victims frequently report very low levels of self-esteem and a lack of confidence.
* Victims rarely stand up for themselves when confronted face-to-face by bullies.
* Bullying victims may lack social skills and friends and are often raised in overprotective households.
* Victims often are physically undersized and weaker than their peers.
* Contrary to popular belief, physical characteristics such as obesity, dress, or wearing eyeglasses have not been shown to be factors that correlate with victimization.
Victims suffer long-term consequences .

* Students who are bullied often see school as an unsafe and unhappy place. Seven percent of American eighth graders will stay home from school at least once a month because of bullying.
* Students who are already social outcasts may find themselves even lonelier when they become victims of bullying.
* Being a victim of bullying brings consequences that can follow an individual well into adulthood, including depression, low self-esteem, other mental health disorders, and, in rare cases, even suicide.
* Studies have found that victims who were bullied as children are more likely to be bullied as teenagers and adults.

Not in every case. This cause and effect is not justifiable. There are many people who have been bullied and the bullying gave them to guts to become tough and resilient. On the other hand some people are affected by it and it can ruin their self-esteem. I have a friend who was viciously physically abused by their father but their self-image remained intact. The abuse prompted them to not give in and to become tough. A lot of it depends on parents. If a parent teaches a child how to face adversity they will be resilient and vice versa. Emotional support when dealing with adversity can make the difference in someone’s life.