Supporters for animal personhood insist they are riding the coattails of previous groups who have overthrown the status of non-persons. Slaves, women and children once had their freedoms and dignity denied, since they were considered property or inferior underlings. The fight for their basic rights is a precedent for bestowing personhood to non-human yet highly intelligent and sociable mammals. Advocates also promise numerous benefits to mammals once their new rights are established. They will be again free, no longer held captive in zoos, circuses, aquariums and scientific laboratories.