من ال thesis عرفنا وحده من الاسباب وهي تجي بأول جمله من البرجراف البودي الاول topic sentense
2 Recent research reveals that some individuals are genetically predisposed to
shyness. In other words, some people are born shy. Researchers say that between 15 and 20
percent of newborn babies show signs of shyness: they are quieter and more vigilant.
Researchers have identified physiological differences between sociable and shy babies that
show up as early as two months. In one study, two-month-olds who were later identified as
shy children reacted with signs of stress to stimuli such as moving mobiles and tape
recordings of human voices: increased heart rates, jerky movements of arms and legs, and
excessive crying. Further evidence of the genetic basis of shyness is the fact that parents
and grandparents of shy children more often say that they were shy as children than parents
and grandparents of non-shy children (Henderson and Zimbardo 6).2