Which children are more likely to suffer from anxiety — extraverts or introverts? How does childhood temperament relate to adulthood? Here at SteadyHealth, we like to get straight to the point, so we'll give you a spoiler — "today's youth" would disinterestedly utter a "duh", and be done with it. They'd be right. At the same time, isn't quite that simple. Introverts come in several types, you see, and preferring solitary activities certainly doesn't have to be pathological. How do you tell the difference?
Did You Know There Are Two Types Of Introverts?
Introversion and extraversion (colloquially usually spelled "extroversion" for some reason) are frequently thrown-about terms — but what do they really mean? The Myers-Briggs Foundation holds that introverts primarily energize through reflection on the world of ideas in their own minds, frequently in solitude, while extraverts recharge their mental batteries primarily through social interaction .
Not all introverts are fundamentally the same, however — they can actually be divided into two categories. Type A introverts are self-reliant, confident, and self-actualizing, while Type B introverts have low self-confidence, are shy, withdrawn, lack communication skills, and display fear of social interaction. 
Childhood Introversion, Shyness, And Anxiety: Is There A Link?
The umbrella of anxiety disorders encompasses a wide spectrum of different conditions, ranging from generalized anxiety disorder to obsessive compulsive disorder, and from social anxiety disorder to specific phobias . All these anxiety disorders manifest differently, and we cannot say that shyness — or Type B introversion — is correlated with all of them.
Social anxiety disorder, the symptoms of which are a fear of unfamiliar social situations, the scrutiny of others, and embarrassing oneself through a lack of social skills , was found to be significantly more common among shy and introverted individuals than among non-shy people. However, we still have to note that most shy individuals do not suffer from social anxiety disorder — the two are in no way synonymous. 
Separation anxiety in children, which accounts of half of all cases of childhood anxiety disorders , could also be said to manifest as shyness — which others may interpret as introversion. Excessive anxiety surrounding separation from primary attachment figures, typically parents, would lead to an impaired ability to interact with other people, after all. 
Interestingly, one study further found that people who rated themselves as having been "very shy" during childhood had an increased risk of suffering from social anxiety disorder in adulthood, even where they were not diagnosed with this anxiety disorder as children . Another study found that 42 percent of those adolescents who were shy during early childhood struggled with anxiety, compared to a much lower 11 percent of those who were not shy. Once again, a majority of adolescents with anxiety had not been shy as children, but the link is strong enough to be clinically significant. 
How To Tell If Your Kid Is Just Introverted, Or Actually Anxious
Is your child perfectly able to interact with other people — but do they simply prefer solitude over social interaction a lot of the time, gravitating away from team activities and towards tasks they can do on their own? A confident, happy child who loves to spend time "in their head", with books, or engaged in quiet solitary activities, who simply needs that alone time to thrive, might well simply be a Type A introvert. 
If, on the other hand, your child finds it extremely difficult to get along with others, if they are fearful of social interactions, if your child worries about everything, and if they have low self confidence, you will want to undertake steps to help them feel better. A full evaluation is in order in this case. Pediatric psychologists and psychiatrists can help asses whether your child might be suffering from an anxiety disorder, along with social workers and your primary care provider (family physician or pediatrician).
Meanwhile, you may wish to get a clearer idea of what is going on with your child yourself, as well. You may find it helpful to take a look at both the parent and child versions of the Screen for Child Related Anxiety Disorders (SCARED) [12, 13]. The SCARED questionnaires are, when used by a qualified mental health professional, able to help identify a wide range of anxiety and related disorders, but you as a parent will certainly also find them useful in deciding whether you need to seek professional help for your child.