at verbal communication. Richard Branson, known for his Virgin brand of over 360 companies is a notable example, as is Charles R. Schwab the founder and CEO of the Charles Schwab Corporation. Pablo Picasso, Tom Cruise, and Whoopi Goldberg are other examples of dyslexics, considered "slow" as children. The autism spectrum of psychological conditions affects about 0.6% of children, characterized by widespread abnormalities of social interactions and communication, severely-restricted interests, and highly-repetitive behavior. Notable individuals with autism spectrum disorders include Tim Page, a Pulitzer Prize-winning critic and author and Vernon L. Smith, a Nobel Laureate in economics. Adolescents During adolescence a youth goes through physical and mental changes that lead to them becoming an adult. Adolescence is usually considered to start with the first stages of puberty and to continue until physical growth is complete, although the World Health Organization defines adolescence simply as the period between ages 10 and 20. There is a wide range of normal ages, but generally girls begin the process of puberty between the ages of 8 and 13, while boys usually start between the ages of 9 and 14. The entire process of puberty typically takes up to 4 years, with girls usually finishing around age 14, and boys at age 15-16. "Late bloomer" can refer to children who suffer from delayed puberty, who are late in reaching their full height. W. B. Yeats (age 30), Pierre Trudeau (age at least 28), Mark Twain (age 34), and Johann von Goethe (age 39) are all "late bloomers" in this last sense. In most public educational systems, children and adolescents of the same age are put in the same classes. Because of the wide variance in the onset of adolescence, this means that one class may include individuals who have not yet started puberty, others who are sexually mature but not fully grown and yet others who are effectively adult. During this period, there is a high risk of an adolescent dropping out of formal education (due most commonly to laziness, intellectual boredom, bullying, or rebellion) without having achieved their full learning potential. The term "late-bloomer" may refer to such an individual who develops serious intellectual interests in their 20s or 30s and enrolls in college, where he or she performs particularly well and subsequently establishes a professional career. Adults A late blooming adult is a person who does not discover their talents and abilities until