Tattooing began at least as early as 8000 B.C. Early Christians used special symbols to identify their members, but the custom soon died out in Europe. It continued to develop in the East, however, and British Naval Captain James Cook's sailors brought back tattoos from a 1769 voyage to Tahiti. The tattoo became the badge of an adventurous life; it has also been used for centuries to mark prisoners and criminals. Outlaws and inmates in many cultures often elect to mark themselves with designs that document their crimes, sentences, and beliefs. American criminals of the late 1880s had a distinct dislike for antisocial tattoos, possibly being more cautious than their European peers about providing the police clues of identity. The rate of tattooing on criminals in this country began to rise in the 1930s. The records of approximately 15 percent of Idaho Territorial and State Penitentiary inmates selected at random show a 1,000 percent increase since the 1880s in incoming inmates with tattoos. One Idaho prison official estimates that 90 percent of today's Idaho inmates receive tattoos while in prison, although tattooing is strictly forbidden by all U.S. prison rules and the tattoo artist and the inmate receiving the tattoo are disciplined equally. However, prison officials are in a quandary; if rules are too tight, the practice is driven underground and standards of hygiene deteriorate. One of the negative aspects of prison tattoos is their identification of the individual as a former inmate, which can elicit negative responses from, among others, prospective employers. Several studies have shown that tattooed inmates feel more positive about their bodies, are more assertive, uninhibited, and extroverted than nontattooed inmates. They exhibit less self-discipline but are less likely to talk about crime. A 1972 study showed that prisoners with tattoos generally had more education than those without tattoos, those convicted of felonies have more tattoos than those with misdemeanor charges, and those charged with crimes against people wear more tattoos than those charged with crimes against property. Psychologists who have studied inmates with tattoos have traditionally focused on the negative, pathological side of the practice; few researchers have looked at the expressive role which tattooing plays in prison culture.