Changes

==Time Frame==

==Time Frame==

Puberty usually starts in girls at ages 10-11 and in boys at ages 11-12.<ref name="Kail">{{cite book| last = Kail | first = RV |author2=Cavanaugh JC | title = Human Development: A Lifespan View | isbn = 0495600377 | publisher = [[Cengage Learning]] | year = 2010|accessdate= September 11, 2014| page = 296 | edition = 5th|url=http://books.google.ca/books?id=E-n5E7oyCgoC&pg=PA296#v=onepage&q&f=false}}</ref><ref name="pamf.org""</ref> Women usually finish puberty at ages 15-17, men at ages 16-17. The process takes different lengths of time for different people based on genetic factors and societal factors such as food supply and nutrition. The average age of the beginning of puberty has decreased measurably over time, particularly in females.[http://www.medicinenet.com/puberty/article.htm]

Puberty usually starts in girls at ages 10-11 and in boys at ages 11-12.<ref name="Kail">{{cite book| last = Kail | first = RV |author2=Cavanaugh JC | title = Human Development: A Lifespan View | isbn = 0495600377 | publisher = [[Cengage Learning]] | year = 2010|accessdate= September 11, 2014| page = 296 | edition = 5th|url=http://books.google.ca/books?id=E-n5E7oyCgoC&pg=PA296#v=onepage&q&f=false}}</ref><ref name="pamf.org""</ref> Women usually finish puberty at ages 15-17, men at ages 16-17. The process takes different lengths of time for different people based on genetic factors and societal factors such as food supply and nutrition. The average age of the beginning of puberty has decreased measurably over time, particularly in females.[http://www.medicinenet.com/puberty/article.htm]

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