When it comes to satisfaction, all jobs are not created equal. One new study seeks to determine what makes us love—or want to leave—our occupations.

Police officers, librarians, janitors and more: find out in our rollover page which jobs offer the most satisfaction…and the least.How’s they figure?

Are you a priest, firefighter or physical therapist? If so, you have one of the three most satisfying jobs in the country.

The prestige and respect in a community associated with a career have a lot to do with whether or not people are satisfied with their jobs, according to the results of the General Social Survey (GSS), a comprehensive study conducted by the University of Chicago’s National Opinion Research Center between 1988 and 2006.

But among the very top-ranked occupations, which also include psychologists and teachers, another common thread appears. In interviews with nearly 30,000 Americans, researchers found that professions that involve caring for, protecting and educating others exhibit the highest levels of job satisfaction.

A staggering 87 percent of priests and clergy members said they were “very satisfied,” compared with to 80 percent of firefighters and 78 percent of physical therapists. People in creative jobs, such as painters, sculptors and authors also felt positively about their work.

Surprisingly, doctors and lawyers—both very well paid and prestigious careers—were absent among the top 12 most satisfying fields. GSS Director Tom Smith believes that this may be due to the stress and great responsibility attached to those occupations.

Satisfied workers also tend to be the same people that are happy in general in their lives. Overall, about 47 percent of people said they were very satisfied with their jobs, and 33 percent said they were very happy.

When it comes to overall happiness, the clergy again ranked highest, with 67 percent describing themselves as “very happy.” Firefighters and ticket agents tied for second place, with 57 percent feeling “very happy.”

On the other hand, job satisfaction was very low for manual labor, food preparation and service occupations. Roofers were the least satisfied, with only 25 percent saying their job was satisfying. Other jobs with low satisfaction included waiters and servers, laborers, bartenders and cashiers.

The unhappiest workers were garage and service station attendants (13 percent were “very happy”), roofers (14 percent) and casting machine operators (11 percent).

So if you are looking for happiness and satisfaction in your job, you should go into a respectable field that directly helps people.

How were they tested?

The job satisfaction and happiness is part of a larger study called the General Social Survey (GSS), supported by the National Science Foundation.

Researchers conducted face-to-face interviews with a representative sample of randomly selected people. A total of 27,587 people were interviewed for the job satisfaction and happiness portion of the survey.

Of the 500 categories of jobs (as listed in the U.S. Census Classification of Occupation, 1980 edition), 198 categories had a significant amount of people to be reported in the GSS.