The Ph.D. degree is a research degree, designed to train a scholar to be able to do original research of publishable quality in his or her chosen field.
Just the facts:
2 million: number of men in 2012 earning a PhD.
1.8 million: number of women earning PhD in the same year.
But between 2002 and 2012 the gap between the number of men and women with professional degrees shrank.
History of the Doctorate Degree
9th Century: Originated in the schools of the Muslim world before spreading to European universities. As in a Doctor of Laws degree, this degree was limited to Islamic law at the time.
1150: first Ph.D. awarded in Paris
FACT: Before the 19th century, professional doctoral degrees could only be awarded in theology (Th.D.), medicine (M.D.), or law (J.D.)
Early 1800s: When the Ph.D. first gained its status as the highest academic honor.
Friedrich Wilhelm University in Berlin, Germany, was the first university to award a Ph.D.
The Ph.D. spread to the United States in the 1800s.
1861: Yale University was the first American school to award the degree.
1876: First Ph.D. awarded to an African-American, Yale University
In 1900, the Ph.D. spread to Canada
1960s: fewer than 25,000 Ph.D.s awarded annually.
282: Number of U.S. Universities that now offer Ph.D. programs
60,000: number of doctoral degrees awarded annually by American universities (to U.S. citizens and non citizens).
Roughly ½ of those 60,000 are granted by the 63 research institutions in the elite Association of American Universities. The other half from other doctoral-granting programs.
How Long Does it Take to Earn a Ph.D. (in the U.S.)?
34: Average age of a recipient
8.5: median time lapse between earning a bachelor’s degree and earning a Ph.D. in the U.S.: 8.5 years in the humanities; 7 years in Mathematics, Physics of the Life Sciences. U.S.
5: Number of years it takes to earn comparable Ph.D.s in European Universities.
Skillsets Needed:
• Ability to design, conduct, and evaluate research,
• Write for scholarly and popular audiences, and to
• Manage the most complex ideas at the highest levels
Hardest Ph.D. programs
• Engineering: i.e. software engineering, systems engineering, chemical engineering, mechanical engineering, civil engineering, financial engineering
Downside: They’re grueling endurance courses in which you will be pushed to the absolute limits of your intellectual and academic capabilities.
Upside: Can provide routes for you to rise to the top of your field.
• Med school: doctor, doctor
Downside: years of schooling, years of intensive training
Upside: There is always a need for doctor
• Chemistry
Downside: intensive schooling, research
Upside: job demand. You’ll find a job quickly
Easiest Ph.Ds (not counting Diploma Mills)
• Business: upside, can take courses online. Downside: busy field
• Information Technology: Upside: Expertise needed in this information society 
Downside: Glut of graduates
• Psychology: upside: Online Ph.d programs acceptable. Downside: Unemployment. Too many Ph.Ds in this area
Some Reasons ($$$) to get a Ph.D.: Nice R.O.I.
Unemployment Rate:
• Ph.D.: 2.5%
• Master’s Degree: 3.5 %
• Bachelor’s Degree: 4.5 %
• Some college, no degree: 7.7 %
• High School Diploma: 8.3 %
• Less than a High School Diploma: 12.4 %
Median Weekly Earnings:
• Ph.D.: $1,624
• Master’s Degree: $1,300
• Bachelor’s Degree: $1,066
• Some college, no degree: $727
• High School Diploma: $652
• Less than a High School Diploma: $471
FACT: On average, Ph.Ds will earn $1.3 million more than baccalaureate holders, over their working lifetimes.
Some of the most in demand degrees (based on in demand job openings)
• Biomedical engineers
• Network systems and data communications analysts
3. Medical scientists
4. Biochemists
5. Mental health counselors
• Medical Degree. Average total debt: $126,000. Average annual salary: $183,900
• Doctor of Pharmacy. Average total debt: $66,319. Annual income: $106,630
• Lawyer. Average debt: $82,000. Annual income, on average: $129,120.
WARNING: Watch out for diploma mills: The way to see if degrees are genuine and not awarded by diploma mills is to check if the school is accredited by an agency acknowledged by the Council for Higher Education Accreditation.
4 Weirdest Ph.D. degrees
• Landscape architecture Ph.D.: offered by Edinburgh College of Art, a 36-96 months part time course.
• Pastoral counseling Ph.D.: Liberty University
• Organizational Leadership: The Chicago School of Professional Psychology
• Advanced Topics in Sexual Issues: North Central University
10 Youngest Ph.D.s EVER
• Akshay Venkatesh, 20: Mathematics, Princeton U. {now teaches at Stanford)
• Erik Demaine, 19, Mathematics, U. of Waterloo, Canada (now teaches at M.I.T.)
• Charles Homer Haskins, 19, History, Johns Hopkins (taught at Harvard) Haskins earned his degree in 1890.
• Juliet Beni, 19, Psychology, University of California Riverside (teaches now at UCR)
• Sho Yano, 18, Molecular Genetics and Cell Biology, University of Chicago (went on to earn an M.D. at age 21)
• Norbert Weiner, 18, Mathematical Logic, Harvard (worked on cybernetics…in early 1900s)
• Ruth Lawrence, 17, Mathematics, Oxford University (taught at Hebrew University, Jerusalem)
• Balamurali Ambati, 17, Medicine, Mount Sinai School of Medicine, New York City (making him the world’s youngest doctor)
• Kim Ung-Yong, 15, Mathematics, Civil Engineer, Colorado State U. (teaches at Chungbuk National University, South Korea)
• Karl Witte (born in 1800), achieved Ph.D. at 13, Philosophy, University of Giessen, Germany (researcher, scholar)
Celebrities… You Might Be Surprised… Who Have Doctorates
• Mayim Bialik (famous for starring in the TV show Blossom): Ph.D. in neuroscience
• Brian May (lead guitarist, Queen): Dr. May is an astrophysicist
• James Franco (actor): English
• Dolph Lundgren (hunky actor): chemical engineering
Sources:
http://www.census.gov/newsroom/releases/archives/education/cb13-13.html
http://www.ehow.com/about_5257288_history-phd-degree.html
http://phdcourse.net/united-states/united-states/
http://www.bls.gov/emp/ep_chart_001.htm
http://www.phdprogramsonline.org/5-weirdest-p-h-d-programs-in-the-usa.html
http://chronicle.com/article/The-Future-of-the-PhD/131749/
http://talk.collegeconfidential.com/graduate-school/366367-why-does-take-so-long-get-phd-certain-fields.html
http://www.donaldasher.com/articles/myths_phd.html
http://www.petersons.com/graduate-schools/phd-engineering-programs.aspx
http://www.gradschoolhub.com/10-youngest-people-ever-to-achieve-a-doctorate-degree/
http://www.thefrisky.com/photos/10-celebrities-who-have-doctorates/doctor-mayim-bialik-jpg/
http://www.cnn.com/2010/LIVING/12/30/cb.popular.graduate.degrees/
http://www.kiplinger.com/slideshow/business/T012-S001-5-advanced-degrees-still-worth-the-debt/index.html
http://www.abika.com/Reports/Samples/Verifycollegedegree.htm
http://talk.collegeconfidential.com/college-life/936964-hardest-type-graduate-school-2.html