A majority are male, white and Christian, with a higher level of education than the average American. The average age of members is in the early 50s, and most were lawyers before entering public service.
That's according to an absorbing new report from the Congressional Research Service, which used information from the CQ Press Electronic Library as well as CQ Roll Call's Guide to the New Congress to compile demographic information about members of the legislative branch from 1945 to the present. The report, which includes racial, educational and occupational information, demonstrates that even as those elected to make national laws have become more diverse culturally, they're also more religious and more likely to serve as career politicians.
As Time Goes On, Congress Gets Older
Between the 79th and current 112th Congress, representatives haven't changed significantly when it comes to age.
The median age of members of Congress is above that of the U.S. population, which the report attributes to the fact that a U.S. representative must be at least 25 years old, while a senator must be 30 or older. While the median age of the U.S. population was reportedly 30 or younger until the 102nd Congress (1991 to 1993), the 2010 U.S. Census reports the median age now hovers around 37.2 years.
Still, the average age of those in Congress has always been considerably higher than that of the population at large. Even at the beginning of the 79th Congress in 1945, when Americans' life expectancy was much lower, the average age of representatives was 52.7 while senators were slightly older at 58.9. The average age didn't fluctuate significantly until after the 102nd Congress, when it began to slowly climb each session, reaching its highest point in the 111th, when the average House member was almost 57 and the average senator just over 63.
Elected officials are also holding onto their seats longer than ever. The average length of service increased during the last half of the 20th century, from an average of 7.1 years (House) and 8.2 years (Senate) during the 79th Congress, to 9.8 years (House) and 11.4 years (Senate) today.
During the early history of Congress, turnover in membership was frequent and resignations were commonplace. During the 20th century, congressional careers lengthened as turnover decreased as congressional service became more of a career, the report states.
While members of the House and Senate had an array of careers before entering the legislature -- such as astronauts, journalists, professional athletes and entertainers -- a majority of lawmakers have generally come from similar occupational backgrounds.
Since 1945, the most frequently reported occupations of U.S. Representatives and Senators has been as followed: law, banking or business, agriculture, education and congressional aide. Representatives have held a wider variety of positions than senators, according to the report, who have reportedly held about 38 different primary occupations since 1945, compared to 21 among senators.
Law has been the most commonly cited profession over time in both the House and Senate, although it has been declining since the 97th Congress (1981-1983). Those with agricultural backgrounds have also decreased enormously since the 82nd Congress, while individuals with banking or business experience have been gaining more seats since the 97th Congress.
Still, law has dominated both houses since 1945 -- between 20 percent and 25 percent of all elected representatives have identified law as their first occupation, while among senators that figure is even higher at between 30 percent and 50 percent.
Race and Gender
At the beginning of the 112th Congress, 96 of the 100 senators were white, while two identified as Hispanic and two as Asian-American.
Since 1945, senators identifying as Hispanic have ranged from 0 percent to a high of 3.1 percent at the outset of the 111th Congress. Those identifying as Asian-American have ranged between 0 percent and a high of 3 percent in the 97th Congress. However, no more than 1 percent of senators in each of the Congresses examined identified as either African American or American Indian.
Although the House has been slightly more diverse over the years, it was still more than 90 percent white until the 107th Congress (2001-2003). The second largest racial group to serve during the period studied are African Americans, who made up 0.5 percent of the House at the start of the 79th Congress until reaching a high of 9.7 percent at the beginning of the 112th. Hispanics, who accounted for 0.2 percent of representatives during the 79th Congress, reached a high of 5.5 percent in the 11th and 112th sessions. Asian-American representation -- of which there was none on the 79th -- is 1.6 percent of the current House.
American Indian representation, on the other hand, has fluctuated between 0 and 0.2 percent.
Although Congress has slowly become more diverse over the years, it still does not come close to accurately representing the U.S. population. The 2010 U.S. Census reports 72.4 percent of Americans are White, 16.3 percent Hispanic, 12.6 percent black or African American, 4.8 percent Asian, while 0.9 percent identified as either an American Indian or Alaska Native.
Congressional representation is particularly disproportionate when it comes to women. While there has been at least one woman serving in the House since the 68th Congress (1923-1925), and in the Senate since 1932 (with the exception of the 79th, 93rd, and 94th Congress') female representation -- until this day -- has never surpassed 17.3 percent.
Based on House membership, the United States ranks 71st among the world's democracies in representation by women, according to the Inter-Parliamentary Union.
Congress Identifies As Christian at Higher Rate Than U.S. Population
Data indicate that members of Congress identify a religious affiliation in dramatically higher proportions than the U.S. population. In both chambers, lawmakers identifying an affiliation expanded through the 102nd Congress, although it has decreased since then.
Although 97.7 percent of the 79th Congress identified as Christian -- the highest on record -- the CQ press only provided information for 32 Senators and 172 Representatives. Since then, that proportion has increased. For instance, in the 112th Congress, 92 senators and 404 representatives reported their faith affiliation, which is primarily Christian or Jewish.
In the current House of Representatives, more than 90 percent of members have identified themselves as a Christian, with a majority of that group -- 56.1 percent -- reporting they belong to a Protestant denomination. Meanwhile, 6.2 percent identified as Jewish, 2.3 percent identified as Mormon and 6 percent didn't specify.
In the Senate, 85 percent of members identified themselves as Christian, also dominated by a Protestant majority, while 13.2 percent are Jewish and just over 1 percent didn't specify. Among the Congresses analyzed, there have been no Muslim or Buddhist senators.
Among the general population, more than 16 percent of Americans aren't affiliated with a religion, according to a 2007 report by the Pew Forum on Religion and Public Life. Among respondents, 78 percent identified as belonging to a Christian denomination, 1.7 percent were Jewish and about 0.6 percent were Muslim.